When attempting to treat a biting problem, you must first get to the root of what is causing the problem before you can begin any treatment. There are four basic reasons that make rats want to bite.
Firstly, females may bite when protecting their nests or their young. This is a natural behaviour caused by hormones produced while pregnant and nursing. This behaviour usually stops when the babies are weaned, or sometimes earlier.
Secondly, sometimes rats get what is called ‘cage-aggressive’. A cage-aggressive animal is one that is protecting its entire cage like it is his nest, and will not let a human hand near, though he will not protest to being picked up outside of his cage. This behaviour is rarely curable, especially in adults. The only thing you can really do is to entice the rat out from its cage with a treat before attempting to pick him up.
Thirdly, rats will often nip if they can smell food or other rats or any other animal on your hands. You can help prevent this behaviour by washing your hands with an unscented soap before attempting to pick up your rats. If bites occur, you can usually train the rats not to bite you by using the squeek method. When the rat nips your hand, squeek in a high-pitched voice and pull away quickly. This, in rodent language, means, “That hurt!”. The rat should realize that it is hurting you and stop. This method also works for rats who nip fingers through their cage bars. You should never feed rats treats through the bars of their cage, because when you put your finger near they will automatically expect food and probably bite your finger. A trick that may help these rats that are so excited about food that they would nip their owner is to give them small cut up pieces of cardboard through the bars. It may take a while, but soon they will learn that not everything that comes through the bars is exciting.
Fourthly, some rats, especially older males and those that have had little handling throughout their lives, are just plain aggressive. Unfortunately, there’s not really anything you can do except try to win his trust. Offer him treats and be nice with him and take it slow. Who knows, he may come around. However, some rats can be perfectly nice pets, then turn on you and attack for no reason at all. This type of spontaneous aggression is usually a severe mental disorder, and cannot be cured. Neutering may help to quell the aggressive tendencies, but it is not always effective.
Of course, the best way to help keep your rat from biting is to first buy animals with great temperaments that do not bite, then continue to handle the animal and never give it reason to bite you. The more handling and socialization it gets, the less the chance there is of it wanting to bite you.
