Some animals, such as squirrels, are notorious for digging up flower bulbs. It is often for this reason that many gardeners dig up and store bulbs that are hardy in their climate for the winter. Before throwing up your hands and letting the squirrels win the battle of the bulbs or before you unnecessarily dig them up for the winter, you can take some measures to keep the squirrels from eating your flower bulbs.
Dip or spray unplanted bulbs with repellent designed for moles or rodents. Then, plant the bulbs as usual.
Place a layer of chicken wire over top of the planting site. Cover this with soil or mulch. The shoots from the bulbs will grow through the holes in the chicken wire.
Spray a repellent spray designed for rodents or moles over top of the mulch after planting. Always follow manufacturer directions.
Build a fence with chicken wire if all else fails. It should be buried at least 6 inches into the ground and extend 30 inches high. Add an additional 6-inch wide layer of chicken wire, flat to the ground along the outside perimeter of the fence to prevent the squirrel from digging their way in to the planting site.