All snakes are carnivorous; they eat other animals. Some are venomous; they inject poison along grooves in their teeth. Some snakes are constrictrors. Constrictors are not venomous, so they squeeze their prey to death. Snakes swallow their food whole, and they cannot chew. Because snakes are cold-blooded, they do not have to eat as regularly as mammals. People who own pet snakes feed them as infrequently as once per month. Some snakes can go as long as six months without a good meal.