If you find yourself caring for baby rabbits, whether you recently adopted them, found them abandoned or have a pet that gave birth, determining their age is the first step to figuring out exactly what care they need. It is difficult even for experts to determine a rabbit's exact age without examining the bones and eye lenses post-mortem, but with a few physical and behavioral clues, you can get a rough estimate of your rabbit's age.
Check if its eyes are open. Baby rabbits open their eyes at approximately 10 days; this is also the age where they become more adventurous. If your baby rabbit's eyes are open, and it is moving in small, tentative walk-like hops, it most likely is between 10 and 14 days old. At this age, rabbits' ears perk up and look more rabbit-like, and cotton tails, which are hairless at birth, develop a full coat.
Observe its behavior. If your rabbit is exploring further from the nest and clearly developing its leg strength, it likely is approaching 1 to 2 months old. In the wild, 4- to 5-week-old rabbits begin to leave the nest and explore their surroundings, though they return to their mother to sleep. At this age, you should start bunny-proofing your home to protect your belongings from your curious rabbit. This is also important because by about 3 months old, young rabbits have entered their adolescence. Like humans, adolescent rabbits experience hormonal and behavioral changes at this time. For rabbits, this usually means chewing anything they can get their teeth into and sometimes urinating and defecating anywhere and everywhere. This can be a very frustrating time for rabbit owners, but it means your rabbit is approaching maturity.
Take your rabbit to a veterinarian. Look for a vet that specializes in rabbits and small animals. A specialist will have a better idea of how old your rabbit actually is. This visit is especially important for newborn rabbits abandoned by their mother, as rabbits under 10 days old rarely survive, even in the most experienced hands, when left to be raised by humans. Visiting a vet also is beneficial as your rabbit reaches maturity. When your rabbit enters adolescence, it is time to talk about spaying or neutering. The procedure will keep your pet rabbit happy and healthy and make your life easier.