Hello! Im sorry to hear about your problem but I feel your pain. I have the same problem. I've been told that mine are hickory nuts that fall from my trees but they look the same as yours. I just bought the property a few months ago, so all of this is new to me. I have slipped a few times while walking over them, but my main problem is when I try to cut grass near them with my zero turn I can hear the nuts cracking and damaging my blades I'm sure. I guess I need to buy a jack so I can look under the mower and see if the blades have been damaged. Also, as I'm sure you know, they make your lawn look messy and wet. I have a 5 acre lot, so I'm not looking forward to raking! Lol!