Fipronil is a broad-use insecticide that belongs to the phenylpyrazole chemical family. Fipronil is a broad-spectrum insecticide that disrupts the insect central nervous system by blocking the passage of chloride ions through the GABA receptor and glutamate-gated chloride (GluCl) channels, components of the central nervous system. This causes hyperexcitation of contaminated insects' nerves and muscles. Specificity of fipronil on insects may come from a better efficacy on GABA receptor, but also because GluCl channels do not exist in mammals. Fipronil is a slow acting poison. When used as bait, it allows the poisoned insect time to return to the colony or harborage. In cockroaches, the feces and carcass can contain sufficient residual pesticide to kill others in the same nesting site. Fipronil is one of the main chemical causes blamed for the spread of colony collapse disorder among bees.