betterwithcats.net
Cats are not monogamous animals. Female cats in heat love to seek out many mates. This is why is it possible for same litter of cats to have different feline fathers!
Female cats enter multiple stages of fertility over the year. During this stage, female cats are likely to mate with several males - for 10 to even 20 times per day!
Male cats search for an available female. Many of them have to fight with other males to get their chance to mate. These fights can get pretty bad, and can also transmit Feline Immunodeficiency Virus.
If a female cat mates with more than one male cat, her litter of kittens might have different fathers. This phenomenon is called Superfecundation.
Most of big cats are also not monogamous, just like our domestics cats. So, cats are not animals that will mate for life.
1. Spaying helps reducing breast tumors in cats 2. Neutering helps reducing chances of testicular cancer in dogs 3. Spay/neutering decreases chances for annoying vocalization and cat's roaming behavior