Probably one of the least useful traps is poison-based. It’s not that the poison doesn’t work, because it is generally pretty effective. The trick with these sorts of traps is two-fold. One, it depends on the squirrel wanting to eat the poison over more appetizing material like nuts and fruit. Two, it doesn’t kill instantly, so once the flying squirrel eats the poison, it could end up dying somewhere random within the attic, or even the house itself. Many people have noted rodents dying inside the walls of their houses. Obviously, a dead animal festering in the attic or walls is not ideal, as it can allow for the spread of insects and might even attract other animals.