Do you have a dog or a cat? If you adopted your pet, you're smart! Ever wonder where shelters get all their animals? Sometimes people let their dogs and cats have litters, and then can't find homes for the babies. Some unlucky pets get lost and are found roaming the streets.

Life on the street is tough for dogs and cats. They don't get regular meals and become sick. It's such a hard life that most strays will not live more than a year or two, and the worst part is when stray animals mate and have babies. Cats can start having kittens at four and a half months of age, and dogs can have puppies at six months of age. And they can have litters every three months – that's four times a year!

If one cat had six kittens every three months for five years – and if those kittens have kittens – can you figure out how many cats would be born in total? There are too many animals and not enough homes for them all! That is a good way to explain pet overpopulation. Put an end to pet overpopulation and you can help, too. Sterilize to save a life!