It means that an animal is ready for mating. It begins to act strange and meows a LOT if it is a cat XD.
they are ready to have kittens
If your yorkies vagina is big, it might mean she is about to go into heat, leaving the state of it. Or She is just in heat
An ambiguous question. How young? And what do you mean by going crazy?
Male dogs can not go into heat.
heat danger
yes mares go in heat in November they usually come in heat in spring and are on and off heat for a while
Sometimes polar bears go in heat
No, a cat will not go into heat if she is already pregnant.
A certain heat degree.
the sun absorbs heat
it means it will be attracted to heat
The Latin noun calor can mean heat, warmth, passion, zeal, ardour or love.