The "extra tooth problem" is universal in carnivores; indeed, in all mammals--its just not often noticed. In most mammals, the deciduous (baby) teeth remain for immediate use until the permanent teeth have grown in place. This is not just for the canines, but for the incisors, premolars and molars as well. In humans the process can take several weeks, with noticable toothy grins during the eruption of the permanent tooth. But carnivores need their teeth to survive, so the baby teeth remain as long as possible, while the permanent teeth grow under, beside, or behind the baby teeph. As the permanent teeth grow (from the crown down) the deciduous teeth disolve (from the root tip up). About the time there is enough root to stabilize the permanent tooth, the baby tooth has lost enough root to become unstable. In most cases, the process is well timed, with one dropping out just as the other is nearly fully erupted, but sometimes the timing is off, and one comes in or drops out early. Usually, the tooth comes loose while eating, and is swallowed. The entire process can appear to be very rapid, and unless you look carefully, you would never see the process going on at all. Teeth are very hard and last well in the fossil record, so there are thousands of articles concerning aging animals by their teeth. Within a species, tooth eruption is fairly predictable, and the age of the animal can be (usually) predicted to within a week or so. Nutrition, calcium intake, disease, and environment can shorten or lengthen the time scale, but generally, 8 to 9 weeks is about right for the replacement of the lower canines. (I must point out that breeds of ferrets with shorter faces tend to have more dental problems than those with longer faces. I know nothing about judging, or what is "preferred," but those who wish to develop such varieties should study the problems that plague short-faced dog and cat breeds. These animals may or may not follow the tooth replacement timetable most other ferrets follow. This comment is not referring to the normal shorter face of the ferret when compared to the polecat, but to "pugs.") There is the occassional ferret that has extra, or supernumerary teeth. This most often occurs in the front teeth (incisors) and is almost always harmless. Nothing needs to be done unless the extra tooth physically effects the position or use of another tooth. If you suspect such problems, let a vet open the hood and take a look-see. Pulling the tooth cures the problem. BTW, the ferret only has 4 molars; one on each side, top and bottom. It is way in the back, and is very small. (In cats, its even smaller) The big, sharply pointed tooth is a premolar specially adapted for cutting or shearing meat and bone. Technically, when you watch a ferret eat dry pelleted food, it is not chewing as much as it is cutting the pellet into small enough chunks to swallow. Often, you will see the little guys twist their heads sideways while eating, or eat things out of the side of their mouth, which helps get the food onto that cutting tooth (I really notice this when they are eating sticky foods. Bear will actually roll over trying to get the sticky raisin onto the tooth for cutting). Poole reported noticing ferrets fed dry pellets had alot more wear on this tooth than those fed wet or natural diets, and could distingish feral fitch from captive domesticates based on this criteria. Bob and the Toothy 13 [Posted in FML issue 1467]