It’s a bit hard to make out in the photo, but there the center is a larger black insect being swarmed by dozens of small light brown ones. The larger one looks like some sort of beetle. What are the smaller ones?
It’s probably beetle mites, see German Wikipedia article for a post cture similar to yours, unfortunately the English contains only a close up.
Here a translation by DeepL of the introduction and the section on its way of life:
The common beetle mite (Parasitus coleoptratorum) is a species of mite that is often found as an ectoparasite on beetles.
The species lives on the dung of large mammals, for example horse dung, where it feeds predatorily on threadworms and other tiny creatures such as fungi. If the dung dries out, the deutonymphs mount dung beetles en masse and allow themselves to be carried to a new substrate. Only when this is fresh do they descend and develop into adults, which only live for 6-10 days. Oviposition takes place on the hosts. The species is fully grown after three moults.
So they’re not actually beetle parasites but just use them as transportation? That’s cool!
I somehow forgot to include a sentence from the properties section:
Some of the mites live ectoparasitically on beetles and are also phoretic here, as they utilize the transport capacity of their host.
I think this implies they also drink the ‘blood’ of the beetle while being transported to another place.
Thanks. More creepy bug stuff I didn’t know about. The beetle seemed inhibited if not incapacitated by them. It looked to me like a swarming attack, but it could have just been that there were so many that it couldn’t easily move.