Trombidiidae, also known as red velvet mites, true velvet mites,[2] or rain bugs, are small arachnids (eight-legged arthropods) found in plant litter and are known for their bright red color.

[2][3][4] This also makes them the largest mites, if disregarding ticks engorged after feeding;[5] unlike those, D. tinctorum and T. grandissimum are harmless to humans.

[3][4] Their life pattern is in stages similar to other members of the Prostigmata: egg, pre-larva, larva, protonymph, deutonymph, tritonymph and adult (male or female).

[9] One well-known species from Europe, Asia, and North Africa is Trombidium holosericeum.

[6][11] According to Joanna Makol[12] The oil from the red velvet mite Trombidium grandissimum is used in traditional Indian medicine to treat paralysis.