Insectivore

An insectivore is an organism that consumes insects as part of its diet. This term can apply to both animals and plants. Another term used for this behavior is entomophage. This word can also describe the human practice of eating insects. Insects are incredibly abundant across the globe. They make up a massive portion of animal biomass in most non-polar and non-marine environments. Scientists estimate the global insect biomass is about 10^12 kg, which is one billion tons. The total population is estimated at 10^18 organisms, or one billion billion.

Many creatures rely on insects as their primary food source. Other animals use insects as a protein supplement, especially during breeding seasons. Even though insects are small, they provide essential nutrition for a vast range of life. This includes many different species of fish, such as carp. It also includes amphibians like frogs and various reptiles like geckos and chameleons. Some birds, including swallows and nightingales, are also insectivores.

Insectivory is found in many different types of mammals. Some are small, like shrews or bats. Others are quite large, such as the giant anteater or the aardvark. The sloth bear is perhaps the largest mammal recorded as an insectivore. Even some primates, such as tarsiers and aye-ayes, eat insects. Some scientists suggest the earliest primates were nocturnal, tree-dwelling insectivores.

Evolutionary history shows how this feeding habit began. The first vertebrate insectivores were amphibians that lived 400 million years ago. Originally, these amphibians were piscivores, meaning they ate fish. They possessed sharp, conical teeth similar to those of a modern crocodile. This tooth structure was also effective for eating insects with hard exoskeletons. This ability likely allowed the transition from eating fish to eating insects.

In the past, scientists used a specific classification for certain mammals. They grouped them into an order called Insectivora. However, this order has since been abandoned. Researchers discovered that not all insectivorous mammals are closely related. Most of these taxa have been reclassified into new groups. Those that remain related to one another are now placed in the order Eulipotyphla.

Some plants have also evolved to be insectivores to survive in harsh locations. These plants often grow in acidic bogs or rocky areas where the soil is poor. These environments lack essential minerals like nitrogen, potassium, and other trace elements. To compensate, these plants trap and consume animals or protozoans. While they get nutrients from prey, they still get most of their energy from photosynthesis.

These plants use spectacular mechanisms to secure their food. Some use pitfall traps or bladder-traps to catch prey. Others use sticky surfaces, hair-trigger snaps, or even lobster-pot trap mechanisms. Examples include the Venus flytrap, pitcher plants, and sundews. While they are called insectivorous, they can actually consume any animal they catch. Some large pitcher plants have even been known to consume small vertebrates like lizards or rodents.