Necrophoresis or corpse-ridding or "undertaking" behavior, is a behaviour seen in ant

Ant

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

s and other social insects

Eusociality

Eusociality is a term used for the highest level of social organization in a hierarchical classification....

. The behavior helps maintain good sanitation in the insect colony. Ants recognize death by the absence of certain chemical signals present in living individuals or by the presence of compounds produced in decomposition.

In ant colonies, there are some worker ants that specifically maintain the hygiene of the colony by undertaking or necrophory. Oleic acid

Oleic acid

Oleic acid is a monounsaturated omega-9 fatty acid found in various animal and vegetable fats. It has the formula CH37CH=CH7COOH. It is an odorless, colourless oil, although commercial samples may be yellowish. The trans isomer of oleic acid is called elaidic acid...

 has been identified as the compound released from dead ants that triggers necrophoric behaviour in Atta mexicana while workers of Linepithema humile react to the absence of characteristic chemicals (dolichodial and iridomyrmecin

Iridomyrmecin

Iridomyrmecin is a defensive chemical, classified as an iridoid, isolated from ants of the genus Iridomyrmex. Iridomyrmecin is also found in a variety of plants including Actinidia polygama....

) present on the cuticle of their living nestmates.