no they don't NEED a big prey, they are perfectly fine on whatever as long as they're getting all nutrients they need in a healthy way. Having said that I do feed mice, adults or smaller, sometimes more then once a month, they are my garbage disposals lol if one of the snakes refuses the mouse instead of going to the garbage it goes to my pacs. Since it is seasonal, usually oct-dec when snakes are on a hunger strike, so they are getting more then once a month sometimes during this time, and none during off season. after such a meal they are off food for at least a week or week and a half and on nightcrawlers after that.