Another Creepy Crawlie

I found a thingy in my garden yesterday. It was bigger than an ant but smaller than a fly and wobbled. It started hissing when it saw me. A cross between an alarm and a mating call.

It seemed to want to go underground in the soft earth. But what was it and why had it suddenly appeared?

It was as though it was suddenly born and decided my garden could be its home. I need to set up a thingy preservation society. A private rewilding project. A creepy crawlie enclave.