Australia's Science Forum

New Discovery:

""Scientists have discovered that crocodiles and alligators have extremely sensitive touch sensors on their skin that are more sensitive to vibrations than human fingertips. This is surprising considering that the bodies of these reptiles are covered with hard protective scales. The sensors are called integumentary sensor organs or ISOs and appear as dark spots. A nerve bundle known as the trigeminal ganglia connects these spots to the animal's brain.
According to researcher Duncan Leitch, "We didn't expect these spots to be so sensitive because the animals are so heavily armored." The most sensitive ISOs were found near the mouth and teeth of the reptiles. This level of sensitivity around the mouth allows them to identify the prey that they catch. It also provides the sensitivity needed for female crocodiles and alligators to delicately pick up their eggs and young hatchlings with their mouths."""
from Science Daily

Does this mean that when they go to take a big bite of you they can tell whether you are tasty or not before they even chew you

Yah, and if they dont like you, they spit the bits out!! Charming

Good one sunray, that is a great read.

Yes it is a great read, but not too surprising really. One of the ways they communicate is to vibrate the water, and the intensity of the vibration indicates mood/size etc. Kind of like snakes on the ground, they seem to be able to detect what is potential prey in the water, and what is just a branch falling off a tree.