What does it mean when an animal is in heat?
When a animal or a pet is in heat that means that your pet or animal is able to reproduce at that time. If you fix your pet this won't happen.
common to when female humans get their period.
only most mammalian females are said to be in heat when they want to mate.Heat period is also called estrous and it is part of estrous cycle which is found in female lion tiger cat cattle rat rabbit etc.