Raccoons are nocturnal animals most commonly identified by the dark, black circles around their eyes. Although raccoons appear cute and cuddly, they can be aggressive and do not like humans. It is not uncommon for raccoons to take up residence under the deck of a home. Getting rid of raccoons under a deck is important, because they carry disease and can be dangerous for both humans and household pets. Raccoons can also be destructive to your property, eating your pet's food, digging in your trash cans, tearing up insulation and destroying whatever they need to get food.
Place a radio on the deck or near the deck. Turn the radio on and tune it to a talk-radio station.
Set the volume low enough that it does not disturb your family or your neighbors. Raccoons dislike humans and the sound of the human voice will scare raccoons. The volume has to be just loud enough that it can be heard below the deck.
Leave the radio on day and night for a few days in a row. You will eventually notice that the raccoons have left the deck and are not returning. If the raccoons are not leaving, increase the volume level a bit.
Saturate about five rags with full-strength household ammonia. If your deck is large, use more rags.
Toss the rags in various spots under the deck. If you are not able to reach suitably under the deck, fill a squirt bottle with ammonia and squirt it all around under the deck.
Reapply the ammonia every couple of days until there is no sight of the raccoons.