Original: Some species have very generalised diets but many taxa have narrow prey preferences (stenophagy) and correlated morphological specialisations, e.g. for feeding on other snakes, elongate burrowing lizards, squamate eggs, mammals, birds, frogs, fish, etc.
Simplified: They have also adapted themselves, to better be able to feed on other snakes, certain lizards, squamate eggs, mammals, birds, frogs, fish, etc.