Raccoons are a natural scavenger. While they do not typically enter a house, they will rip into garbage cans or even tear the singles off of a rooftop in search of insects or other things to eat. There are instance when a raccoon will enter a home to make a nest, however, because it is warm. They can enter into attics or chimneys and will often build nests and give birth in these areas. They are not usually aggressive, although they can become so if they feel threatened.
Not only are raccoons carriers for a number of diseases that they can pass onto domesticated pets, they are also considered to be a major nuisance around the house with the mess they make and leave behind. While there are many outdoor scavengers, raccoons usually leave very distinct paw prints around the areas they have gotten into.
Once you have identified that a raccoon is the problem, the solution may be that you will need to invest in a raccoon repellent to keep them away.
Make sure that any outdoor garbage cans are well-sealed will help keep raccoons from tearing them apart in search of food. Sometimes hooking a bungee cord over the top of a garbage can will prevent a raccoon from lifting the lid off.
However a very persistent raccoon may try to chew through the cord. In that case, you may want to secure the lids with metal, such as a chain, or place a heavy weight on the top of a can, such as a large rock.
Raccoons have a very strong sense of smell, so repellents that manipulate their senses may work well, such as those that use urine-like, predatory scents to keep them away from a certain area. Another benefit of these is that they are usually non-toxic and safe for use around the house and any local plant life.
The latest raccoon deterrent devices include leds that mimic predators eyes at night, scaring away the raccoons.