Factors influencing the chemical release of prey attack in newborn snakes.

Attack behavior of inexperienced garter snakes to water extracts of normally eaten prey was investigated. Since eliminating vision and olfaction in newborn snakes did not alter response to chemical cues, Jacobson's organ is considered to be the receptor most involved. Slight variations in age and concentration did not affect potency of an extract, but, over a wider range of concentration, the relationship between extract concentration and releasing value appeared logarithmic. Raising newborn snakes on an artificial force-fed diet for over 6 mo. did not alter the prey-attack behavior itself or the relative effectiveness of extracts from a variety of organisms. This "releasing mechanism" is resistant to stimulus and response deprivation.