Editing Pheromone (section)

===Trail===
{{Main|Trail pheromone}}
Social insects commonly use trail pheromones. For example, [[ant]]s mark their paths with pheromones consisting of volatile [[hydrocarbon]]s. Certain ants lay down an initial trail of pheromones as they return to the nest with food. This trail attracts other ants and serves as a guide.<ref>{{cite web |url= http://www.news.cornell.edu/releases/Feb98/antpheromone.hrs.html | title= Excited ants follow pheromone trail of same chemical they will use to paralyze their prey | access-date= 2006-03-14}}</ref> As long as the food source remains available, visiting ants will continuously renew the pheromone trail. The pheromone requires continuous renewal because it evaporates quickly. When the food supply begins to dwindle, the trail-making ceases. Pharaoh ants (''[[Monomorium pharaonis]]'') mark trails that no longer lead to food with a repellent pheromone, which causes avoidance behaviour in ants.<ref>{{cite journal | vauthors = Robinson EJ, Green KE, Jenner EA, Holcombe M, Ratnieks FL | title = Decay rates of attractive and repellent pheromones in an ant foraging trail network. | journal = Insectes Sociaux | date = 2008 | volume = 55 | issue = 3 | pages = 246–251  | doi = 10.1007/s00040-008-0994-5 | s2cid = 27760894 | url = http://eprints.whiterose.ac.uk/46214/1/RobinsonPheromoneDecayInsSoc.pdf }}</ref>
Repellent trail markers may help ants to undertake more efficient collective exploration.<ref>
{{cite journal | vauthors = Hunt ER, Franks NR, Baddeley RJ | title = The Bayesian superorganism: externalized memories facilitate distributed sampling | journal = Journal of the Royal Society, Interface | volume = 17 | issue = 167 | pages = 20190848 | date = June 2020 | pmid = 32546115 | pmc = 7328406 | doi = 10.1098/rsif.2019.0848 | doi-access = free }}</ref> 
The army ant ''[[Eciton burchellii]]'' provides an example of using pheromones to mark and maintain foraging paths. When species of wasps such as ''[[Polybia sericea]]'' found new nests, they use pheromones to lead the rest of the colony to the new nesting site.

Gregarious caterpillars, such as the [[Forest tent caterpillar moth|forest tent caterpillar]], lay down pheromone trails that are used to achieve group movement.<ref>{{cite journal | vauthors = Fitzgerald TD | title = Use of pheromone mimic to cause the disintegration and collapse of colonies of tent caterpillars ( Malacosoma spp.). | journal = Journal of Applied Entomology | date = July 2008 | volume = 132 | issue = 6 | pages = 451–460 | doi = 10.1111/j.1439-0418.2008.01286.x | s2cid = 83824574 }}
</ref>