A recent study by Vanderbilt Graduate Student Duncan Leitch shows that the raised domes along crocodiles' heads are just as sensitive, if not more so, than our own hands.
"The dots are extremely sensitive touch receptors...My professor and I didn't believe at first that they could be that reactive. We closed our eyes and tried to tickle each other with [the filaments used to test the crocodile's response] on our fingertips, and neither of us could even feel it," he says.
National Geographic explains that the bumps are actually integumetary sensory organs (ISOs) which allow the crocs to feel slight ripples as they search for prey.
Leitch notes, "Many times alligators will snap very quickly after touching something....What's interesting to me is that such a scaly animal, one so heavily armored, could have a sensitivity that rivals or surpasses our tacticle abilities. But they have all these little tactile areas that are so exquisitely sensitive--it seems really amazing."
The team's research uncovered that the domes connected to the trigeminal nerve, which is "associated with biting, chewing, and swallowing," according to Nat Geo.
By studying the crocodile's ISOs, Leitch and his professor hope to better understand the human brain.
"The same nerve that is in human beings that is responsible for touch and movement in our face, it helps us get a better idea of how nervous systems are adapted for unique situations," states the graduate student.
Co-chair of the Association of Zoos & Aquariums' Crocodilian Advisory Group says "This was exactly what I had hoped somebody would do with ISOs, in terms of really looking at the distribution and the electrophysiology, because that's really the way to answer these questions about function in a tiny sense organ like this."
The study was originally published in The Journal of Experimental Biology.