I used to have a bed of Oriental and Asiatic lilies.... In Asia, lily bulbs are considered an edible delicacy. Apparently chipmunks know this too. My lilies started getting smaller every year, so I dug them up to see what was going on. The main bulb was completely demolished (chewed up), and the scales were scattered in the ground so that I had baby lilies trying to grow everywhere.
I also found a stash of sunflowers nearby.
I believe the chipmunks stumbled on the lilies by accident while hiding their cheekpouchful of winter stores.
Eventually, the lilies died out (I could've taken better care of the babies but wasn't able to) until one summer, instead of lilies, all I got were 3 clumps of sunflowers sprouting together. "What the..... WHERE are my lilies!"