Cat overpopulation by the numbers
Kittens are adorable, but it is important to remember that kittens quickly grow up to be cats, who unless sterilized tend to make many more kittens. Millions of cats and dogs are euthanized in shelters every year, because there aren't enough loving homes for them. Each new kitten has to compete for survival.
The average litter size for a cat is four kittens, but they can have many more. A cat can also have several litters in a year; they are able to get pregnant while still nursing. Estimates show just one unspayed female can produce as many as 3,500 kittens in a 12 year lifespan.
Of course, the male cats play their part too. A male cat can sire 2,500 kittens in one single year.
A female can and will breed with multiple males, and one litter of kittens can have more than one father. Some estimates count that one intact couple and their offspring can result in 420,000 cats in seven years, provided they all survive.
Many believe siblings won't mate, but cats don't share the human sentiment of ethics. Given the chance, a brother and sister will have a litter, and it is important to sterilize the cats in the household, even if they're siblings.
Help the cats out through spaying and neutering!