What are the signs of a female cat in heat?

A female cat’s heat has four stages with different signs. Stage 1 (proestrus): vaginal discharge and a swollen, congested vulva.

Stage 2: she is anxious and cries loudly; when touched or her rear pressed, she raises her rump and lifts her tail. She sprays urine with a strong odor and eats much less, even refusing food. Stage 3: she accepts the male mounting. Stage 4 (metestrus): heat behavior fades and stops.