Young ferrets may be frightened by sudden movement from above, especially if it is accompanied by a loud noise. This is probably a reflex inherited from their wild ancestors, the weasels and polecats, who were preyed on mainly by large birds. A fear reaction in a young ferret is dramatic. The ferret will hunch his back, open his mouth and hiss, fluff out his tail and body hair (piloerection), and sometimes screech, a sound that alarms other ferrets (and people) in the area. If he is not descented, the ferret may release the strong smelling secretion in his anal sacs. This whole series of events is a defense reaction designed to scare off the attacker.
Older ferrets rarely show this fear reaction unless truly attacked by another animal, and some become so trusting they don't even do it then. Talk quietly to a kit that shows a fear reaction, and don't try to pick her up unless it is necessary to prevent her from falling or escaping outside. In a few minutes, the kit will realize it's a false alarm and go back to her normal self.
Pet ferrets that accidentally get outside may be so frightened that they turn on their owners in panic, and should be approached cautiously if they demonstrate the piloerection reaction. Never attempt to pick up a ferret in this state of fear. The ferret may bite viciously, hard, and often, causing severe wounds that may require sutures. If the ferret is out in the open, it may be possible to drop a coat or towel over him, and leave him in the quiet and dark until he is less frightened, or until someone can put on a pair of thick leather gloves to capture the animal. Talk quietly to the ferret and do not make sudden or noisy moves until he has a chance to calm down. It is astounding how fast an alarmed ferret can move, and you may not have a second chance to catch him.
Mothers with kits
She bit me! Some jills with babies will attack strangers who reach into the nest to pick up their kits, a justifiable defense on their part. They bite hard, intending to hurt you as much as possible. If you move your arm or hand away from the nest, with the jill still attached to it, she will usually let go of you and return to her babies. The best way to avoid this kind of bite is not to disturb a jill with newborn kits.
Kits and juvenile play
Most baby animals chew and mouth things, and ferrets are no exception. Kits play by wrestling and gripping each other's necks with their teeth. Until they learn otherwise, they expect to do this with people too. Babies may bite very hard if they are hungry, because they haven't learned to distinguish food from fingers.
Many ferret lovers deny that ferrets would hurt you on purpose unless they are frightened, but biting is natural behavior in young ferrets. They have sharp teeth and can hurt you if they bite and hang on, and it is good to know how to deal with this situation without getting severely injured. Juvenile males, especially those that have lived most of their lives in a pet shop without much handling, occasionally grab people as they do each other. They take a firm grip, clamp down as hard as they can, and shake their heads. This doesn't hurt other ferrets much, but human skin is not nearly as thick as ferret hide, and we have no protective hair covering, so that kind of treatment causes real pain.
If your ferret bites
Don't pull on the ferret! The harder you try to pull the ferret loose, the tighter he will hold on, and the more pain it causes you. You can not pry the ferret's teeth apart because he has very strong jaws and is very determined. Sometimes if you press the ferret's lips against his molar teeth he will release his grip long enough for you to free yourself. There are several other tricks to make a biting ferret let go.
Don't hit the ferret! Hitting a biting ferret anywhere on his body will usually cause him to hang on tighter and shake his head harder, causing you more pain. A very frightened ferret may also become more frenzied and bite viciously rather than playfully. Do not underestimate the damage a ferret can do with his teeth: these are predatory animals, designed to survive skirmishes with rats, which are fearsome adversaries. You can discourage some ill-mannered ferrets from biting by snapping them hard on the end of the nose with a finger, but if you don't move the second the ferret lets go, he will usually make another attempt to bite.
Being shaken vigorously often discourages them. This is the way ferrets punish each other: a mother ferret disciplining a kit holds the kit by the scruff of the neck and shakes it. Don't shake the ferret so hard that he could become injured, just bounce him back and forth or up and down enough to get his attention, and immediately move your hands out of range of his teeth when he lets you go, which he almost always will do.
Shaking more gently also works to distract a young ferret that is determined to bite your fingers when you pick her up - constantly bouncing the ferret appears to interest her rather than alarming her, and will save you many nips when you cannot put the pet down and must restrain her for longer than she prefers to sit still. This technique is also used as a distraction by the mothers of fretful human babies.
Ferrets that bite hard and are really hurting you, and will not let go with a shake or a nose snap, will usually turn loose if you put them under running water, head first. Occasionally a really determined one thinks this is just part of the game and grimly hangs on anyway. The last resort is to put something either very bitter or very sweet in the ferret's mouth with the blunt end of a pencil or pen. Sometimes the pencil itself tastes interesting and the ferret will let go of your arm or hand to try something new. Liquid soap tastes awful but is harmless in the amount required to make a biting ferret let go. It is better not to use a sweet treat if you can avoid it, as rewarding the ferret for biting is not your goal. It will work as a diversion if there is no handy alternative.
Training your ferret not to bite
Most young ferrets like action every minute they are awake, and they can usually stir up some action if they bite you. If your ferret persistently bites you to get your attention, or bites you every time you pick him (or her) up, put him back in his cage for a while, until he learns that biting is not an acceptable leading move. Accompany every attempt to bite with a firm "No" in a harsh voice, different from the voice you use when you are pleased. It will take what seems like a very long time for these lessons to be learned, but if you persist, you will be rewarded later with a civilized, affectionate animal that is fun to play with and safe to introduce to your friends.
When handling unsocialized juveniles, avoid getting bitten by picking them up quickly and firmly, and don't try to cuddle them until they have learned some manners. When a biter needs to be handled, an experienced person can either hold the ferret by the scruff of its neck, or keep a neck hold, with the thumb and fingers encircling the neck under the jaw so that the ferret can't get his head down to bite.
Ferrets adopted as kits by experienced ferret people rarely develop a biting habit, because the mouthing of human hands is discouraged before it becomes biting. A male adopted when half grown, especially at 12 to 16 weeks of age, is more likely to bite because he has been playing rough games with his ferret companions who don't object very much. It is less common for jills and neutered males to behave this way, but ferrets are individuals and no generalizations can be made. If firmly and patiently corrected, most ferrets that bite because they were unsocialized as kits can become well-mannered pets.