Loud, frequent yowling or crying
Restlessness or pacing
Rolling on the floor
Increased affection or rubbing against people and objects
Raising the hindquarters and moving the tail to the side
Kneading with the back legs
Trying to escape outdoors
Reduced appetite
More frequent urination or urine spraying
Licking the genital area more often
Seeking attention or acting unusually clingy
Signs that come and go in cycles every few weeks