Badgers usually leave wasps nests until they are at their most full and productive peak. Which is August. They find them earlier in the year, but generally wait for this time. It is when the adults are normally at their biggest as well, and the grubs prolific. They are still small very this year and about the size you find them in the spring. But the evidence supports the badgers usual prey of earthworms being hard to find and so they are going after other food sources. Wasps nests being one of the main ones. So far there isn’t any evidence that points to more subterranean nests than usual.