There are also some forms (e.g. Smarididae) that are predators of small invertebrates – including smaller Prostigmata – yet others have a more varied lifestyle (e.g. Tydeidae) or switch their food sources as they mature (e.g. Erythraeidae).

Hydrachnidia live in many kinds of freshwater habitats, including lentic (e.g. lakes, ponds), lotic (e.g. rivers, streams), springs and interstitial waters.

[2] Prostigmata have a wide range of diets, including species that are predators, herbivores, fungivores, microbivores and parasites.

The trombidiform mites are possibly the most promising approach to untangle the systematics, taxonomy and phylogeny of the notoriously complex Acariformes.

Trombidiformes and the other acariform clade, Sarcoptiformes, were formerly considered suborders but this does not allow for a sufficiently precise classification of the mites and is adjusted in more modern treatments.

The delimitation and interrelationships of these groups are entirely unclear; while most analyses find one of the latter two but not the other to be a subgroup of the Anystina, neither of these mutually contradicting hypotheses is very robust; possibly this is a simple error because phylogenetic software usually fails in handling non-dichotomous phylogenies.

[9] As of May 2022[update], Catalogue of Life and Integrated Taxonomic Information System accept the following taxonomy for Prostigmata, including four infraorders:[10][11] (Also known as Eleutherengonides)