rattlesnake

Take a whiff of mustard or wasabi and you'll be hit with a familiar burning sensation. That's the result of chemicals in these pungent foods hitting a protein called TRPA1, a molecular alarm that warns us about irritating substances. The same protein does a similar job in other animals, but rattlesnakes and vipers have put their version of TRPA1 to a more impressive and murderous purpose. They use it to sense the body heat of their prey. Pit vipers are famed for their ability to detect the infrared radiation given off by warm-blooded prey, and none more so than the western diamondback…

It seems like an uneven match. In one corner, the unassuming California ground squirrel (Spermophilus beechyi), 30cm in length. In the other, the northern Pacific rattlesnake (Crotalus oreganos), more than twice the length of the squirrel, and armed with hinged fangs that pack a lethal venom. But thanks to a cunning adaptation, the squirrel often gets an unexpected upper hand in this bout. Ground squirrels live in a series of burrows that keep them out of reach of most predators. Snakes, however, have exactly the right body plan for infiltrating long sinuous tunnels, and it's not surprising…