Insectrol - Insect Killer Spray How to use: For fleas, spray infested areas lightly. Ideally, spray around carpets, skirting boards, bed heads and any other area where activity has been seen. All bed linen should be laundered not sprayed. This product is intended for indoor use. Always apply in well ventilated areas, and avoid heavy spraying on foam-backed carpets, plastics, synthetic tiles and polished surfaces. Exclude animals during application.