Try to find out who his homeowners insurance is with and call them. Insurance companies will get off of any hazard that they know is a ticking time bomb with regards to Liability. I would also contact your local city or parish councilman and get him involved. Make sure you document all calls and conversations for a future suit against said parties. Would bet if these bees are agressive they are probably Africanized and very dangerous. Silverback bees must be exterminated, they cannot be Rehabilitated.