Snakes are a diverse group of squamate reptiles characterized by a unique feeding system and other traits associated with elongation and limblessness. Despite the description of transitional fossil forms, the evolution of the snake feeding system remains poorly understood, partly because only a few snakes have been studied thus far. The idea that the feeding system in most snakes is adapted for consuming relatively large prey is supported by studies on anatomy and functional morphology. Moreover, because snakes are considered to be gape-limited predators, studies of head size and shape have shed light on feeding adaptations. Studies using traditional metrics have shown differences in head size and shape between males and females in many species that are linked to differences in diet. Research that has coupled robust phylogenies with detailed morphology and morphometrics has further demonstrated the adaptive nature of head shape in snakes and revealed striking evolutionary convergences in some clades. Recent studies of snake strikes have begun to reveal surprising capacities that warrant further research. Venoms, venom glands, and venom delivery systems are proving to be more widespread and complex than previously recognized. Some venomous and many nonvenomous snakes constrict prey. Recent studies of constriction have shown previously unexpected responsiveness, strength, and the complex and diverse mechanisms that incapacitate or kill prey. Mechanisms of drinking have proven difficult to resolve, although a new mechanism was proposed recently. Finally, although considerable research has focused on the energetics of digestion, much less is known about the energetics of striking and handling prey. A wide range of research on these and other topics has shown that snakes are a rich group for studying form, function, behavior, ecology, and evolution.