Camping in a site that isn't often used is the number one preventative. Most animals are afraid of people until they learn that we carry delicious food and don't fight back. If you camp where the animals haven't learned this yet, they are much less likely to come calling. Often it'll contain notes about particular animal problems. Shelters usually have hooks or nails for hanging bags of food and equipment.
Some campsites have food storage lockers or contraptions for hanging food.
That's a dead-giveaway that animals are problem visitors at those sites. If you're going to camp there, stow your food out of reach. That includes cooking utensils, toothpaste, sun cream, and garbage. It's better to hang a pack from a tree branch than to leave it lying on the ground even if the branch is only a few feet off the ground. Animals will be less likely to stumble upon your pack.