They aren’t ticks, they’re phoretic mites that use their host to travel! They’re in the subclass Acari, and they’re within Arachnids.
Cropped/full size; for the Cabbage Thistle (Cirsium oleraceum) inaturalist.org/observations/234764368
In the tritonymph stage, the highly mobile predatory mites, obligatory parasites of bumblebees, can transfer from bumblebee to bumblebee from flowers, & arriving in a bumblebee nest, molt into adults
Found on/in Mutinus elegans, https://www.inaturalist.org/observations/234941312