PAM is a 0.5% permethrin solution. You can look up it's half-life via google, but IIRC it's effective for up to 30 days if not exposed to sunlight or water.I don't know much about birds, but IIRC they're rather intolerant of chemicals and poisons, so I would remove them from the room before spraying.If you would prefer to wipe the enclosures using a rag, a much less expensive option is to use NIX lice treatment, a 2 oz bottle in 1 gallon of water also creates a 0.5% permethrin solution.