I can mirror the same experiences as written above. Several years ago I had a serious problem with these little bastards. Some of my mounts were badly damaged, others weren't touched. I have hair slip (loss) on a couple of mounts but what really got me was how they got into the hollows of my antelope horns and ate them from the inside. I have one impala with tiny pinholes all in the tips. I know they were inside the horns of my buffalo, but I can find no outward damage.
I visited my local taxidermist and he explained how he was constantly struggling with the problem. He said he had never seen such a problem as we had been experiencing at that time (this is all in central Texas, north of Austin). He handed me a 1/2 jug of Mount Saver, instructed me on how to apply it and I have been using it ever since.
They are a Dermestid Beetle (carpet beetle) and eat the hair follicle at the base of the hair; this is what causes the hair to fall out. Because horn is a modified hair structure, these beetles will happily eat that as well (I'm talking horn, not antler here). Check your bird mounts as well. The beetles will eat the feathers.
How can you tell if you have a problem? Look for what appears to be fine sawdust at the bases of your horns. Also look for patches of hair that seem to be disturbed...brush that hair and see if it falls off. Look also for their shed skins like seen here:
View attachment 672475
One of the biggest signs for me was seeing the tiny moths in the house; especially at night when the room was mostly dark except for the TV or computer screen. I would see them fly near the light. These moths are tiny, but easily identified by their pale, ivory color with an orangish head.
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These beetles are persistent but are easily killed with the Mount Medix products. Treat ALL of your mounts. I found they especially liked the backside of several whitetail shoulder mounts, where the cape is folded around the backside, against the wall. Seems they really like that dark area and feasted on that area. What a mess...
Initially, I took all my mounts outside and with the Mount Saver mixed in a small spray bottle, I misted the spray all over each mount, paying attention to the bases of horns and any pinholes I could find in the horns. For large antelope like Kudu or Eland, I removed the horns and sprayed up inside them. Mount Saver does have a slight pesticide smell, but it goes away quickly enough. A small price to pay against the cost of fine taxidermy.
Mount Medix is found online here:
https://mountmedix.com/shop
I'd suggest everyone check their taxidermy at least once a year.
Ed Z