'Cheating', also known as 'exploitation', between organisms is a form of
parasitism or specialized
predation in which an organism engages in what appears to be a
mutualistic relationship with another organism, but does not in fact provide any benefit to the other organism. The relationship between the organisms may be
symbiotic, in which case cheating is a form of parasitism, or non-symbiotic, in which case cheating is a form of predation or
herbivory.
Cheating is often found in situations where there are generalized non-specific mutualisms between broad classes of organisms, such as the relationship between
flowering plants and animal
pollinators or between
mycorrhizal fungi and
plants.
Examples
Some insects and birds engage in a behavior called
nectar robbing in which they harvest
nectar without pollinating the plant; nectar robbers are often close relatives or
mimics of pollinating species. Another example would be
myco-heterotrophic plants that take carbon from
fungi in a shared
mycorrhizal network without contributing anything to the fungal symbiont. These parasitic plants act as "mycorrhizal cheaters" in such systems.