thumb|This [[aardwolf skull exhibits greatly reduced molars and carnassials teeth as they are unnecessary for any large, insectivorous animal subsisting on soft insects such as termites. The dentition of a shrew is very different. The aardwolf uses its canine teeth in self-defence; accordingly, they have not been greatly reduced.]]
thumb|A [[Asilidae|robber fly eating a hoverfly]]
thumb|The [[giant anteater, a large insectivorous mammal]]
An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects.
The first vertebrate insectivores were amphibians. When they evolved 400 million years ago, the first amphibians were piscivores, with numerous sharp conical teeth, much like a modern crocodile. The same tooth arrangement is however also suited for eating animals with exoskeletons, thus the ability to eat insects can stem from piscivory.
At one time, insectivorous mammals were scientifically classified in an order called Insectivora. This order is now abandoned, as not all insectivorous mammals are closely related. Most of the Insectivora taxa have been reclassified; those that have not yet been reclassified and found to be truly related to each other remain in the order Eulipotyphla.
Although individually small, insects exist in enormous numbers. Insects make up a very large part of the animal biomass in almost all non-marine, non-polar environments. It has been estimated that the global insect biomass is in the region of 10<sup>12</sup> kg (one billion tons) with an estimated population of 10<sup>18</sup> (one billion billion, or quintillion) organisms. Many creatures depend on insects for their primary diet, and many that do not (and are thus not technically insectivores) nevertheless use insects as a protein supplement, particularly when they are breeding.
Examples
Examples of insectivores include different kinds of species of carp, opossum, frogs, lizards (e.g. chameleons, geckos), nightingales, swallows, echidnas, numbats, anteaters, armadillos, aardvarks, pangolins, aardwolfs, bats, and spiders. Even large mammals are recorded as eating insects; Insectivory also features to various degrees amongst primates, such as marmosets, tamarins, tarsiers, galagos and aye-aye. There is some suggestion that the earliest primates were nocturnal, arboreal insectivores.
Insectivorous plants
alt=|thumb|[[Drosera capensis|Drosera species ]]
Insectivorous plants are plants that derive some of their nutrients from trapping and consuming animals or protozoan. The benefit they derive from their catch varies considerably; in some species, it might include a small part of their nutrient intake and in others it might be an indispensable source of nutrients. As a rule, however, such animal food, however valuable it might be as a source of certain critically important minerals, is not the plants' major source of energy, which they generally derive mainly from photosynthesis.
Insectivorous plants might consume insects and other animal material trapped adventitiously. However, most species to which such food represents an important part of their intake are specifically, often spectacularly, adapted to attract and secure adequate supplies. Their prey animals typically, but not exclusively, comprise insects and other arthropods. Plants highly adapted to reliance on animal food use a variety of mechanisms to secure their prey, such as pitfalls, sticky surfaces, hair-trigger snaps, bladder-traps, entangling furriness, and lobster-pot trap mechanisms.
See also
- Entomophagy
- Consumer-resource systems
- Insectivora
- List of feeding behaviours