It is well tolerated by cats and kittens. It is approved for use on cats and kittens over 2 lb from 8 weeks of age. Bioactivation occurs when the cat eats the product or gets it in their system through exposure to the environment. The highly efficacious indoxacarb agent kills pests on contact, meaning that even if petted or grooming pets bring indoor areas infected with spider mites into contact with Activyl, the active ingredients will kill them.