An animal bite is a wound, usually a puncture or laceration, caused by the teeth. An animal bite usually results in a break in the skin but also includes contusions from the excessive pressure on body tissue from the bite. The contusions can occur without a break in the skin. Bites can be provoked or unprovoked. Other bite attacks may be apparently unprovoked. Biting is a physical action not only describing an attack but it is a normal response in an animal as it eats, carries objects, softens and prepares food for its young, removes ectoparasites from its body surface, removes plant seeds attached to its fur or hair, scratching itself, and grooming other animals. Animal bites often result in serious infections and mortality. Animal bites not only include injuries from the teeth of reptiles, mammals, but fish, and amphibians. Arthropods can also bite and leave injuries. Signs and symptoms Bite wounds can cause a number of signs and symptoms Generalized tissue damage due to tearing and scratching Serious hemorrhage if major blood vessels are pierced Infection by bacteria or other pathogens, including rabies Introduction of venom into the wound by venomous animals such as some snakes Introduction of other irritants into the wound, causing inflammation and itching Classification Bites are usually classified by the type of animal causing the wound. Many different animals are known to bite humans. Vertebrates Companion animals, including dogs, cats, rats, ferrets, and parrots, may bite humans. Wildlife may sometimes bite humans. The bites of various mammals such as bats, skunks, wolves, raccoons, etc. may transmit rabies, which is almost always fatal if left untreated. Human bites are themselves capable of doing great flesh damage, but are particularly known for spreading communicable diseases Involuntary biting injuries due to closed-fist injuries from fists striking teeth (referred to as reverse bite injuries) are a common consequence of fist fights. These have been termed "fight bites". Injuries in which the knuckle joints or tendons of the hand are bitten into tend to be the most serious. Teething infants are known to bite objects to relieve pressure on their growing teeth, and may inadvertently bite people's hands or arms while doing so. Young children may also bite people out of anger or misbehaviour, although this is usually corrected early in the child's life. Reverse bite injury A reverse bite injury (also called a clenched fist injury, closed fist injury,