Frequent scratching, biting, or licking, especially around the neck, back, and base of the tail
Restlessness or seeming uncomfortable
Hair loss or thinning fur from excessive grooming
Small red bumps or irritated skin
Flea dirt, which looks like tiny black specks in the fur or on bedding
Live fleas moving through the fur, especially when parting the coat
Pale gums or signs of weakness in severe infestations
Scabs or crusty spots from scratching
Seeing tiny black specks turn reddish-brown when placed on a damp paper towel
Increased grooming behavior or sudden changes in behavior
Flea eggs or debris in the cat’s bedding, carpet, or furniture
A flea comb catching fleas or flea dirt when brushed through the coat