YES John, they gradually managed to eliminate a large group I planted several years ago. They also love anything with a fleshy tap root and have caused havoc with my Hollyhocks for example. These self seed profusely but a "black" one I had gave up the ghost last year after being attacked on a regular basis. Iris are a great favourite and I made the mistake of planting some at the top of a terrace bounded by a path, they have very strong claws and managed to dig out all the hardcore under the gravel of the path in their efforts to get at the rhizomes. Even after I moved the iris, to avoid having to remake the path every spring, they continued to visit that area so they must have long memories! Much as I love Iris and bulbs I have decided to go with the flow and save myself a lot of heartache, not to mention expense, our property is too large to fence and on the whole we like living with nature.