I used to handle my kits the day they were born. I bred heavily for temperament with the does and tolerance t ome being around the nest boxes. This is important because if there is a dead kit or one that needs to be euthanized or for some reason removed, you have to be able to get into the box without upsetting her. If she does not allow you near the box, see if you can take her out, check the kits and then put a dab of vanilla extract on her nose and put her back. But being able to check the kits is vital. for health and cleaning of the box etc. Also, handling for short times and gently from as early as you can helps make them less adversely reactive to stress later on. I remember opening a cage in my house and having a litter of bunnies just crawl out of the cage and begging to be cuddled. They loved being handled. They were used to it. But other breeders who never handled them ended up with kits that were hand-shy and spooky. My preference is handle gently the moment they are born (and this can be just the slight going in and touching each baby as opposed to actually takingout and holding) and refusing to breed from does or bucks from lines that would not tolerate this. Temperament is part heredity and part what we do with it.