If you live in the city, you probably associate them with filth, or even the spread of disease. If you live in the country, you know they're just a healthy part of the ecosystem. Hi, I'm Janice Creneti. I've been teaching environmental science for about 20 years, and I'm here to talk to you today, about how long rats actually live. Well, it depends. If they're out in the environment somewhere, the answer is usually, until they get eaten by something. Rats are what one of my naturalist friends refer to, as nature's popcorn. They are fed off by so many predators, foxes, and hawks, and owls, and larger predators even, like a mountain lion, so they have to reproduce really quickly, to make sure there's enough food to go around, so they don't usually live very long in the wild, two to three years is pretty typical. Now, rats that are kept as pets in captivity, can average about five years, if they're being taken care of well. There's even a rat that's reported to have lived seven years in captivity. That's pretty unusual. One of the other issues with rats, is that the ones that are kept as pets, tend to be from strains that were originally developed for laboratories, and they're actually genetically predisposed. That means they have a tendency to get really big tumors, and that can actually shorten their lifespan. It can make it difficult for them to move around, even to eat, so in a healthy rat, two to three years, if it's out in the wild, probably between three and five years, if it's in captivity. That's about as long as you're going to get, but in that time, with those rats breeding more often than once a month, they can produce a whole lot of babies, to stay behind. I'm Janice Creneti, and this is how long do rats live?