Bull snake

They prefer to eat small mammals and are an ally of humans in controlling harmful rodents.

An excerpt from the article 17 facts about Bull snake

Rats, squirrels, gophers, moles, and mice are the bull snake's favourite food. They also eat lizards and birds. Sometimes they raid bird nests and consume nestlings or brooding parents.

If their prey is small, bull snakes often consume it alive. They constrict only bigger prey.