Often, people in the U.S., including Florida, where the Coral Snake is found, remember which is the poisonous snake by noting that the Coral Snake has red and yellow bands which touch. The Kingsnake and Milk Snakes have red and yellow bands which are separated by a black band. But, if one goes to Mexico and Central America, this means of identification does not work. Notice the difference in head shape. Predators on snakes in Central America include motmots and kiskadees.
Motmots are funny looking birds which often have a long tail ending in a little tassel-like feather.
Smith painted wooden dowels with color bands and solid colors and watched to see which were attacked and avoided by the avian predators. These birds attacked dowels with solid colors and ones which were banded with a neutral color. The birds pecked slightly at dowels with red and yellow longitudinal stripes but fled abruptly at the sight of tricolor bands similar to those on coral snakes. The response to pattern and banding was quite specific to those types of snakes living in the same range as the birds. And, even a small region of patterning, such as would be found on the head, was enough to elicit the avoidance response.