Tarantulas! Huge, hairy tarantulas! Just kidding. Maybe just a ground squirrel? Those are around here occasionally and I've never seen them make a mound around a hole. They may and I just haven't seen it. If the hole weren't so large, I might think it was an emerging grub of some kind or some of those huge insect eating wasps. Insects can actually move and displace a lot earth when you think about it. Dirt Dauber nests, the paper nests of wasps, fire ant mounds, and of course, tarantula holes
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