Dethlac insect killer spray 250ml kills ants woodlice cockroaches and other crawling insects dethlac is a unique lacquer you dont spray the insect you spray your surfaces once sprayed dethlac dries to a hard clear film which remains fully effective for months even when it rains or if the surface is washed with detergentssimply spray onto window sill or frame skirting board or any non absorbent surface which will be coated with a pesticide that will kill insects for monthsdethlac ca