1. Assess the situation. If the rabbit is in immediate danger, such as being in the middle of the road or being attacked by a predator, take action to protect it. This could involve moving the rabbit to a safe location, such as a nearby bush or under a piece of cover.
2. Don't touch it. Rabbits have a very keen sense of smell and can easily be spooked by human scents. If you handle a baby rabbit, the mother may reject it when you return it to the nest, or she could abandon the entire litter due to the scent confusion.
3. Keep an eye on it. If the rabbit is not in immediate danger, you can keep an eye on it from a distance to see if the mother returns. Rabbits typically feed their young once or twice a day, so if you wait long enough, you may see the mother come back to the nest. If the baby is cold, you can place a warm water bottle under the nest or keep it indoors in a warm, safe place.
4. Check the nest. If you don't see the mother return after a few hours, you can carefully check the nest to see if there are any other babies. If there are, try to reunite the babies with the mother, or place them in a warm, safe place.
5. Contact a wildlife rehabilitator. If you are unable to reunite the baby rabbit with its mother or if the rabbit is injured, you should contact a wildlife rehabilitator. They can provide the necessary care and ensure that the rabbit is released back into the wild when it is old enough.
Remember, it is illegal to keep a wild rabbit as a pet in most states, and it is always best to leave wild animals in their natural habitat whenever possible.