Things You'll Need
Instructions
Sight
Place a statue of a hawk on the deck. Hawks and other large birds of prey are natural predators of squirrels. Be warned that the squirrels will eventually wise up to the fact it is not real.
Let your dog or cat out on the deck; it is sure to keep the squirrels away. When a squirrel sees a deck patrolled by a dog or cat, they will stay up in the trees.
Shine a bright light on the squirrel if it is making house under your deck. Often the light alone will be enough to send it packing.
Spend as much time as possible on your deck during the day. Squirrels are only active during the day so if they see you are outside much of the time, they will move on to another home or deck.
Smell
Rub your deck with a bar of soap in areas where the squirrel enters. The smell of the soap is effective at keeping the squirrel from gnawing as well. Also rub down the tops of your bird feeders.
Hang apple cider vinegar-soaked rags around the squirrel's entry points. The smell will repel the squirrel and other critters as well.
Place corn cobs, peanuts, sunflower seeds and other favorite foods of the squirrel in other parts of the yard. This is called diversion feeding. It distracts the squirrel from where you do not want it.
Sound
Turn a radio on very loud on your deck, if you can do so without disturbing your neighbors. This is particularly effective if you have squirrels nesting under your deck.
Bang pots and pans to startle the squirrels. Also try chasing them off, yelling and making loud noises. The one thing squirrels universally despise is noise. Scaring them away like this will gain you a short respite at the very least.
Blow nesting squirrels with a leaf blower. When squirrels nest under your deck, the only way to remove them is to scare them with this type of noise.