Hammerhead Shark

Hammerhead sharks include nine distinct species within Family Sphyrnidae; though these range in size from about three feet to as large as twenty, all are characterized by a flat, hammer-shaped head that is thought to have begotten their name, though the name ‘hammerhead’ was almost entirely due to the members of Family Sphyrnidae’s obsession with hammering.

‘Do you need me to hang that picture for you?’

To paraphrase Mark Twain1, when all you have is a hammer, everything looks like a nail. Hammerhead sharks extend this metaphor by showing that when your head is a hammer, you’re going to spend most of your free time thinking of what you can hammer next. Most sharks never (or rarely) sleep to avoid sinking to the bottom of the sea and dying, but hammerheads never sleep because their minds are constantly racing as they contemplate where and when they can hammer next. Even if they start to nod off and finally get some rest, they’ll suddenly wonder if a passing ship might have a loose rivet they could fix and, next thing you know, they’re out of bed and putting in their contacts.  Even Ambien doesn’t do anything for them.

‘I couldn’t sleep, so I figured I’d just go practice hammering instead of just lying there driving myself crazy thinking about hammering. Say…you don’t need anything hammered, do you?’

The evolutionary origins of the hammerhead’s cephalic morphology has long been a subject of debate and inquiry, with some scientists proposing that the unique shape functions like a hydrofoil, giving the negatively buoyant hammerheads better swim control; others have suggested that it allows tight maneuvering in pursuit of prey. But pretty much everyone agrees that whatever its origins and proper purpose, a hammerhead would rather be using it to hammer stuff.

‘Want some help assembling that new shelving unit from Ikea?’

Recently, a joint study by the Florida Atlantic University and the Hawaii Institute of Marine Biology found that the spacing of the eyes in the hammerhead shape allowed a wider field of vision while enhancing stereoscopicity, which makes it easier to locate something to hammer. Moreover, the team also found that the wider surface area offers enhanced electrosensory capability, which makes for better hunting and also provides a bigger striking surface when a nail is finally located.

‘I think I see…yes…looks like a nail…wait, it’s a piece of seaweed. Oh well, I’d better give it a few whacks just to be on the safe side.’

With proportionally small mouths, hammerheads consume a great deal, including fish, other sharks, stingrays, and octopuses – whatever is quickest so they can get back to hammering. Of the nine species of hammerheads, three (scalloped, great, and smooth hammerheads) are dangerous to humans, though all are considerably more interested in checking your reflexes for you (don’t say no). Some hammerheads are also known to eat their own young, usually as punishment for improperly hammering something.

Like other sharks, hammerheads are nocturnal solitary hunters, but during the daytime they often form massive circling schools, where they compare stories about how much stuff they’ve recently hammered.

‘I drywalled a whole basement the other day. Incredible.’

Hammerheads are also among the few species that can get suntans from prolonged exposure to sunlight, something that happens frequently when they get a much-coveted roofing job for the summer.

Their interest in hammering things is, of course, not the hammerheads’ fault. They’re just dealing with what they have. If their heads were tool belts, they might be more well-balanced. Even better if their heads were a whole garage. But unfortunately, all they have is a hammer, and so hammer stuff they will. So if and when you want to build your kids a tree house, give a hammerhead a call. They’ll be more than happy to help out, at least with the hammering.


1 The saying ‘If all you have is a hammer, everything looks like a nail’ is frequently attributed to Mark Twain, though this doesn’t appear anywhere in his writings. It is likely a traditional saying, but it is often formally attributed to Abraham H. Maslow’s book The Psychology of Science (1966). That said, anything witty and at the same time cuttingly accurate probably was first uttered by Mark Twain.



Say what you will, but jellyfish, a.k.a ‘jellies’ a.k.a. ‘true jellies’ a.k.a. ‘medusae from the phylum Cnidaria’ (trans. ‘jellyfishes’) have done quite well for themselves in spite of their obvious limitation of lacking any brains.

This is not to be confused with the colloquial expression ‘he/she has no brains’ – meaning that he/she has a physical brain present, yet said brain is a Raiders fan, or said brain is sure it found a system for winning at Keno, or said brain got kinda drunk and argued somewhat convincingly to itself that it was okay to eat a bacon-wrapped hot dog from a street vendor in Tijuana1.

Rather, jellyfish literally have no brains. At all.

‘Hey, I just had an idea. Wait…no…it’s gone.’

Yet succeed they have. Comprised of about 95% water (and 0% brain) jellyfish can be found in stable populations throughout the world’s oceans, from top to bottom and also in freshwater. And there are at least 2,000 different species.  And they accomplished all of this without the benefit of an iPad. Impressive.

Not only have they traveled the world and done fairly well despite their brainlessness, jellyfish also manage to kill and devour their prey and deter predators.  Now, one probably wouldn’t be very afraid of a shark that didn’t have a brain. Or a snake without a brain. Or a bear. Indeed, it might be entirely hilarious if a brainless bear was trying to attack you. There’d surely be a website called watchthisbrainlessbear.com and it would be ‘dedicated to providing the most recent videos of brainless bears trying to do things.’ But yet we all intuitively sense that a jellyfish – even a brainless one – is a different matter altogether. And that intuition turns out to be completely correct.

One of the hallmark features of Cnidarians (and therefore jellyfish) are tiny organelles called nematocysts, which are specialized stinging apparatuses that have been described as miniature ‘cocked guns.’ Embedded in the tentacles (and requiring much less maintenance in salt water than actual cocked guns), nematocysts contain tiny, coiled, often-barbed, poisonous threads that plunge venom into the skin of anything unfortunate enough to brush up against a jellyfish. This effectively paralyzes small prey and has ruined many an impromptu skinny dipping session.

Now I remember. I was going to kill you and eat you. I knew it started with a K.’

Perhaps not so surprising for an animal lacking a brain, the jellyfish developed only one gastrovascular opening for both the mouth and the anus2. Known in the jellyfish community as ‘The Great Mistake,’ the mouth/anus serves to devour plankton, fish, crabs, barnacles and sometimes other jellyfish. And then to poop same meals back out later. Adorable.

The Great Mistake aside, jellyfish reveal one of nature’s nasty little paradoxes: Successful evolving – being the fittest and thus ‘the best’ and going on to make a decent living – does not require a brain. However you turn that over in your massive neural network, it surely must diminish the relative standing of humans in nature. And then when we consider that some people (with brains) on our planet actually consider jellyfish a delicacy (even after being informed that there’s no jelly in them), it only takes us and our giant brains down several more pegs. Which is certainly not anything we look for, but something that still has the benefit of reminding us not to spend so much time wondering 24/7 how we’re doing vis-à-vis everyone else, what it all means, what should we really be doing with our lives, is now a good time to buy a condo, et cetera.

Thanks, jellyfish.

Grade: C-

1 Or said brain works in the local coffee shop and when an Animal Reviewer ordered a ‘half decaf,’ said brain asked the Animal Reviewer what he wanted as the other half.

2 This is why the curriculums of jellyfish dentistry schools are virtually identical to those of their proctology programs. Same book and everything.


Dear readers, fans, friends, and our mothers,

The Animal Review book is soon upon us. Featuring some of your favorite posts from this blog (updated) and new reviews of many surprise animals, The Animal Review: The Genius, Mediocrity, and Breathtaking Stupidity That Is Nature is, as far as we can tell, really a beautiful book, full of full-color photographs and new features galore. We also hope it’s funny. We spent so much time on it that we can’t really tell anymore.

If you’re so inclined, it can be ordered now at Borders, Barnes & Noble, Amazon, Target, or an independent bookstore.

It makes a great gift, even for kids (there’s nothing in it you wouldn’t want them to see), as well as a great way to sound smart and well-informed at any public gathering.

Many thanks to all the readers of this blog for their support and to the people at Bloomsbury USA for theirs.

Kindly yours,

Jacob Lentz & Steve Nash

*Update – Oops*

Animal Review would like to thank another alert reader for pointing out a factual error which might be classified as a disaster. In the Platypus review (our second review after Panda, who kicked things off back in May of 2008) we incorrectly referred to mammals as ‘animals with hair that don’t lay eggs.’ Of course, this joke should have read something like: ‘animals with milk-producing mammary glands that don’t lay eggs, except now for the stupid echidna.’ We stand by our pithy definition as the preferred joke definition of mammals. However, we should have been more accurate (or at least accurate), are terribly embarrassed over the whole thing, and extend a hairy mammalian fist bump to Leo who noticed and reported the blunder.

Sidewinder Rattlesnake

Alternately known as the horned rattler, the sidewinder rattler, and Gary, the sidewinder rattlesnake (Crotalus cerastes, lit. ‘Have you seen this thing move????’) is a relatively small rattlesnake found in the desert covering eastern Arizona, southeastern California, southern Nevada, and the southwestern corner of Utah. Ranging in size from just over a foot to two and a half feet, the sidewinder is a triumph of American engineering and can-do ingenuity whose method of locomotion across hot and shifting desert sands of the southwestern United States1 (and its infrared sensory organs) made it a perfect model for the premiere short-range air-to-air heat-seeking missile in the US arsenal.

‘You know this missile actually started out as a snake, Private?’

The sidewinder rattlesnake exhibits two modes of travel: normal, regular straight-line slither and a truly amazing side-slipping S-shape that powers it quickly over low-traction desert sand while minimizing contact with sweltering silicon. Minimizing energy use, only two points of its body touch the ground at a time. The resulting movement is nearly-hypnotic, having entranced generations of settlers and ranchers who quickly came up with an apt and scary-sounding name for their new neighbor.

‘Show of hands for ‘Joey McSlitherWeird’? And then for ‘Sidewinder’? OK, Sidewinder it is.’

The resulting ‘J’ pattern left behind in sand covered by a sidewinder is one of its distinguishing features. Other features distinguishing it include supraocular scales that give the appearance of horns, added to keep sun and sand from the sidewinders eyes. It can also survive without any water (it gets its supply from its prey of small desert animals). Additionally, females are usually larger than males (unusual among rattlers), and its small size combines with a relatively weak venom to pose only a small threat to human bite victims. Though one report included a story of a man bitten by a single fang of a sidewinder on his finger and quickly treated with antivenom, but within three hours his arm was swollen beyond belief and the pain was described ‘as if the arm had been boiled in oil.’ So it’s probably best to learn to move sideways across the hot desert from a correspondence course.


1 Though it is important to note that the sidewinder also inhabits parts of Mexico, and no Ken Burns special would be complete without acknowledging the many contributions of Mexican and Mexican-American NASA employees to the production of the sidewinder rattlesnake.

*Update* – Animal Review. On Facebook. Whatevs.

Animal Review and the upcoming Animal Review book now have an official page on Facebook.


Why should you go there and join? We’ve been over this in our heads like a billion times, and nothing. We really have zero on this issue. Unfortunately, we realized this AFTER we went through the major hassle of putting it up and uploading our photo and adding links and RSS and all that rigamarole. Honestly, it seemed kinda like a decent idea at the time (our other idea was Animal Review ‘cloud computing,’ but we couldn’t figure out what that meant exactly).

So once again:


Anyway, we’re almost 100% certain that the Animal Review Facebook page will do nothing to improve your life. Our apologies for shoving this on everyone.

Africanized Honey Bees (A.K.A. Killer Bees)

Review Prelude: How to Survive a Killer Bee Attack!

Some Do’s and Dont’s from the experts.


  • Run. In a straight line (it’s faster than a circle) and into the wind (increased drag slows the bees more than it slows you. Bees only took Physics 1 and they always assume no friction).
  • If possible, find shelter. It’s better to be inside a car with 40 bees than outside seriously regretting your profound oversight.
  • Pull your shirt over your head. Why? Killer bees like to sting you in the face. In fact, it’s the only thing they like to do.

Note: If you don’t think you can run fast with your shirt pulled over your head, then clearly you’ve never been attacked by bees. Rest assured, you can run fast with your shirt pulled over your head. You can run really, really, really fast.

It also turns out that you’re amazing at Parkour.


  • Jump in water (the bees will be waiting for you at the surface, and probably not with a piña colada).
  • Swat at the bees (this only attracts them).
  • Immediately remove your pants and underwear. Just saying don’t do that.

Alright. On to the review.

It is strange and unfortunate that there is not a Nobel Prize for Really Bad Mistakes In Science1. This international award could be presented annually in Stockholm by a sad clown wearing a lab coat and goggles, giving scientists that much more of an incentive to get things right for once. Brazilian geneticist Warwick Estevam Kerr would have made a fine nominee. For it was Mr. Kerr who introduced Africanized honey bees (Apis mellifera scutellata) to the Americas.

Oops. Bring out the clown.

It all started in 1956 when Kerr was contracted by the Brazilian Agriculture Ministry to hybridize aggressive, hardy, African honey bees with their relatively gentle-but-hard-working cousins that we all know and love, the European honey bees2. His goal was to selectively breed a super bee that was friendly and produced lots of honey, but liked the weather in the tropics and spoke fluent Portuguese. Everyone was to get rich. That was until some African queen bees escaped from Kerr’s facility in 1957 using a grappling hook made of cafeteria trays and bed sheets.

The full scope of the blunder was not immediately apparent to Kerr. Being a brilliant geneticist, he brilliantly assumed the African queen fugitives would breed with feral bees — thus diluting their infamous aggression. He was half right. Keep in mind that in the world of genetics, 50% is considered pretty good3.

The sole entry from Warwick Kerr’s lab notebook on the day the bees escaped. To a  fault, the man tended towards optimism.

And breed they did, spreading their dominant genes that coded for fury out into Brazil (where one farmer died from more than 1,000 stings) then South and Central America and Mexico before heading towards the southern United States. Here, the news media was waiting in a full-tilt frenzy that surprised even the killer bees. It was mayhem. So crazy were the major news outlets with killer bee fever that they were routinely putting entomologists on television. Actual entomologists. On television. The hysteria may have culminated in 1978, when Hollywood produced a movie starring Michael Caine called The Swarm. Now we had serious actors playing entomologists. That’s how nuts it was. And this was all fifteen years before the first killer-bee fatality on U.S. soil4 (1993).

‘Sorry, communism, but we’re afraid of these now.’

To be fair, our neurotic preoccupation with killer bees is not entirely without cause. They are certainly terrifying. Whereas normal European honey bees are slow to respond to intrusion and limit their defense to a relatively small area, Africanized honey bees will attack a perceived threat (like, say, a hippie gathering flowers) up to 100 feet from the hive, immediately, in far greater numbers and pursue over a much larger area. Africanized bees will give chase for up to ¼ mile from the hive, and are not above hopping on a Vespa if it means stinging you just a few hundred more times.

Bee rage has been neatly standardized by an experiment in which a little felt flag was briefly waved in front of hives with the help of a mechanical arm. European honey bees typically delivered between zero and ten stings to the flag in 30 seconds. In contrast, Africanized bees stung it between 400 and 500 times in the same interval. That little felt flag later passed away at the East Houston Regional Medical Center.

Furthermore, when honey bees sting, they release – along with their venom – an alarm pheromone5 called iso-amyl acetate that, curiously, smells like bananas.  The pheromone is a chemical signal for other bees to attack. Because if there’s anything killer bees hate more than felt flags, it’s a non-banana that still stinks like a banana. It just makes them completely insane. So then more bees attack, which in turn releases more alarm pheromone in a horrifying fruit-scented positive feedback loop.

‘Is that banana?  I think that’s banana.  If that’s banana I am seriously going to lose it right now.’

The venom of Africanized honey bees is no different than European honey bees, nor do they deliver more of it per sting. It’s just that they’re total jerks. Disturb a hive of Africanized bees and you can expect to be pursued by hundreds or even thousands of apoplectic flying syringes (as opposed to the comfortable 20 to 40 norm). And just FYI, the average non-allergic person can withstand about 7 bee stings per pound of body weight before death becomes a real possibility. If you’re allergic to bees, you can use the same formula — just be sure to enter your weight as 1/7th pound.

This is all bad. But on the bright side, Africanized honey bees pollinate plants and plants are crucial to agriculture production everywhere in the blah, blah, blah, blah.

Grade: F

Warwick Estevam Kerr Grade: F-

1 Past winners might also include American chemist Thomas Midgley, Jr., who gave us tetra-ethyl lead additives for gasoline (it turns out that lead in the air is not too helpful) AND chlorofluorocarbon (CFC) a refrigerant/aerosol propellant that helped keep our drinks cold and our hair styles groovy, but also tended to destroy our planet’s vital ozone layer at an alarming rate. Bring out the clown.

2 These are the normal honey bees you prefer. The ones that sting you less than 2,000 times. They were originally imported from Europe.

3 75% is excellent. And 100% is considered practically a sure thing.

4 They’ve killed about 26 since in the US, the latest in Tivoli, Texas. Killer Bees also inhabit New Mexico, Arizona, Nevada, California, Oklahoma, Alabama, Arkansas, Florida, Louisiana and Utah. So maybe take “I love camping and the outdoors!!!!” off your online dating profile now.

5 This is why beekeepers employ smoke. It’s thought to mask the effect of the bee’s alarm pheromone. Neat.