Don't confuse the two: Moles and Voles.
Ground moles (as they're commonly referred to) are the larger of the two with big front paws that resemble a baseball catcher's mitt. They're often associated with a raised tunnel meandering through a yard They are not vegetarians and won't eat bulbs or roots, as a rule. They travel through their tunnels at daybreak, noon and evening in search of trapped insects for food and will use the same tunnel over and over for days or even weeks as a means of obtaining their food. In a sense, they are more helpful than harmful. Voles, the much smaller of the two, are about the size of a large mouse, a large wedge shaped head, short neck and big shoulders made for barging ahead or thrusting through the soil to get at their food. They are vegetarians and prefer high starch content foodstuffs like bulbs and tubers. Most of the damage done by voles is done during the winter, invisibly under the cover of snow or mulch where the ground is not frozen. A good way to combat that is to wait for the ground to freeze at the surface before applying winter mulch.
Squirrels eat tulips, crocos and daffs, etc. and will often transplant some in the lawn. Chipmunks won't eat tulips but love crocos , stripped gophers will dig down under the plant and eat all of them from the bottom. Anything newly planted is a potential feast. The way I work around these little critters is to use chicken wire extensively. With larger tulip beds I lay chicken wire down a couple inches above the planted bulb level, then cover with another couple inches of soil. With newly planted lilies, I lay the chicken wire on top but rake a little soil over it to keep it in place until everything seems to have lost interest. Then I remove it and use it for rabbit fencing later.
One neat thing I do that works really well for small bulb flowers (but not lilies) is to cut the bottom out of '1 gallon' size or larger plastic pot, dig a nice round hole and place the pot about an inch or so below ground level. Then, fill the pot with soil to desired bulb level, place/space the bulbs around and cover them with desired amount of soil. Then, cut a circle of chicken wire somewhat larger than the pot so it can be folded down around the edge of the pot a couple inches. Then backfill the pot and wire all around the outside. You won't lose another bulb to squirrels, chipmunks or gophers. It even looks great to have a few pots planted at random throughout a lawn. The pot itself is hidden from view and it gives the appearance of an nice little clump of flowers blooming here and there.