Research on animal remains include the study on molluscs (archaeomalacology), study of ancient biomolecules (such as aDNA and lipids) even the study of insects (palaeoentomology). The most widespread practice though is research on animal bones, teeth, horn and antlers, that is zooarchaeology. Within this, sub-specialisations may be found such as zooarchaeologists focusing on mammals, small mammals such as rodents, fish or birds only or one may be studious enough to work on all of these classes of materials. Not different from archaeobotany and for the very fact not different from any other kind of archaeological inquiry, zooarchaeologists ask questions about the natural environment within which a settlement operated as well as questions about the economic, social and ideological structure of the society under consideration. Wild but also domestic animals may be used as proxies for climate and give indications on the availability of water and the kind of plant cover in the vicinity of the settlement. Turning to human-animal relationships, extinction, domestication, animal husbandry practices, trade and exchange networks, migration, nomadism and transhumance, socio-economic classes and their access to foodstuffs and related prohibitions, butchery, cooking and possibly ethnicity, regular consumption of animals or elaborated feasts, crafts, settlement layout and use of space in relation to animal keeping, slaughter, process and consumption, ideology, ritual and ceremonial sacrifice. The isotopic or chemical element contents of bone and teeth as well as aDNA are additional studies that help to clarify a number of the above questions.