Frequent loud meowing or yowling
Restlessness or pacing
Rolling on the floor
Increased affection or rubbing against people and objects
Raised hindquarters with tail held to the side
Attempting to escape outdoors
Reduced appetite
Excessive grooming of the genital area
More clingy behavior
Assuming a mating posture when touched on the back
Signs of agitation or irritability
Repeatedly treading with the back legs