Females

• Female cats usually reach sexual maturity between 3 and 9 months old, according to PetPlace.com. At this time, a female cat will begin to behave very affectionately toward people, rubbing herself against you and other household objects due to the buildup of estrogen in her system. She will begin to become much more vocal and yowl loudly to attract a mate. Females come into estrus, also called "heat," between February through September, due to an increase in daylight at this time, though indoor cats exposed to artificial light may experience estrus year-round. Periods of estrus last about 4 to 7 days, with breaks of about 1 to 3 weeks in between, according to Cornell University.
  
  

Males

• Male cats come into sexual maturity between 7 to 12 months old, though they are not physically mature until about 18 months old, according to Pet Place. Once a male cat reaches sexual maturity, he begins to behave more aggressively toward other male cats, getting into physical fights for territory and the right to mate. He may also begin to mark his territory by spraying a pungent-smelling urine on vertical surfaces in and around your home. This urine contains special pheromones which send messages to other cats that this territory belongs to him and that he is available to mate with a receptive female.
  
  

Breeds

• The breed of a cat will affect how quickly it reaches sexual maturity. Shorter haired cats reach puberty earlier than longer-haired breeds and mixed breed cats become sexually mature sooner than purebred cats, according to Cornell University. An exception to the purebred rule are cats belonging to Oriental breeds such as the Siamese and Burmese, who can reach puberty as early as 3-1/2 to 5 months old. Persians generally reach sexual maturity later than other breeds, between 10 and 12 months old. If you plan to breed your cat, wait until it reaches physical maturity, between 18 and 24 months old, before allowing it to mate, according to PetEducation.com.
  
  

Considerations

• Both male and female cats in heat will try to escape your home to the outside to mate with other cats. Male tomcats may congregate around your home when your female cat is in heat, especially at night, so they can try to mate with her. To prevent issues such as behavioral problems, increased vocalization and pregnancy, consider having your cat spayed or neutered. This surgery, also called desexing, removes the sexual reproductive organs of your cat, decreasing its levels of reproductive hormones and eliminating mating behaviors. Most veterinarians will only perform this surgery before or after your female cat comes into estrus. Desexing prevents the spread of diseases to your cat, reduces the chances of some types of cancers and prevents pet overpopulation.