Abstract: An insect repellent-containing clay litter material capable of retaining the insect repellent until wetted and then releasing the insect repellent to nearby animals, e.g., cats urinating into the litter material. The insect repellent is impregnated into particles of the clay litter material, and the particles then are coated with a film of water-soluble polymer. When the insect repellent-containing clay is wetted on its polymer coated surface with liquid animal dross, particularly animal urine, such as cat urine, the polymer film is solubilized to permit escape of the insect repellent from the clay particles and the insect repellent is volatilized. Optionally, fragrance impregnated into the litter material together with the insect repellent, continues to provide a fresh smell to the litter material, while the volatile insect repellent, continues to repel invading insects, particularly if the litter box is maintained outdoors.