According to House Rabbit Society, baby rabbits spend between 10 to 11 days in the nest on average. However, according to The Humane Society, it can take up to three weeks before they reach the size of a chipmunk and leave the nest.
Even if a rabbit is left alone in the wild, a baby rabbit is rarely actually orphaned. House Rabbit Society warns that bunnies should be left alone since their mother usually comes to nurse them every morning and evening. Despite their small size, fully-furred bunnies with open eyes and erect ears are strong enough to move around and do not need human help.