What Is Chewing The Base Of Bearded Iris Leaves

Question From: NEVADA
Q: My bearded iris that have been in place and divided for 25 yrs now (and never before) has a pest which is chewing the base of the leaves and leaving those toppled-over leaves. It's like iris carnage. Chew marks are evident at the base of the fallen leaves, and the damage is spreading from one small planting to the next one some 10' away. My guess is rodent because of the size of the chew marks. Ideas?

A: My guess is squirrels, however voles have been known to chew on the rhizomes, Best And Happy Yardening, Nancy.