There are many problems associated with using poison to deal with a rat problem. Firstly, using poison is a very inhumane way to deal with the creatures and causes undue pain and suffering as they slowly die from the poison, they don’t simply drop dead without knowing what’s happened. This slow death then causes a second problem. Rats, just like any other wounded animal will instinctively go somewhere they feel safe in the hopes of waiting out whatever ails them. Therefore, they will go somewhere probably quite secret and hard to reach. This means that when they eventually do die, the carcass will be very hard to find and if you don’t find it, there will be a very bad smell that will quickly emit from the carcass. Another issue with using poison is that if the rat leaves the attic and then dies and another animal finds the carcass and eats it, the poison will hurt them also. In short, you should always use traps instead of poison.