Symbiosis thumb|Acacia collinsii stipules thumb|Swollen stipules of Acacia drepanolobium that serve as ant domatia. An entry hole can be seen at the base of one of the spines of the largest domatia. From the MHNT In the Central American bullthorn acacias—Acacia sphaerocephala, Acacia cornigera and Acacia collinsii — some of the spiny stipules are large, swollen and hollow. These afford shelter for several species of Pseudomyrmex ants, which feed on extrafloral nectaries on the leaf-stalk and small lipid-rich food-bodies at the tips of the leaflets called Beltian bodies. In return, the ants add protection to the plant against herbivores. Some species of ants will also remove competing plants around the acacia, cutting off the offending plants' leaves with their jaws and ultimately killing them. Other associated ant species appear to do nothing to benefit their hosts.
Symbiosis thumb|Acacia collinsii stipules thumb|Swollen stipules of Acacia drepanolobium that serve as ant domatia. An entry hole can be seen at the base of one of the spines of the largest domatia. From the MHNT In the Central American bullthorn acacias—Acacia sphaerocephala, Acacia cornigera and Acacia collinsii — some of the spiny stipules are large, swollen and hollow. These afford shelter for several species of Pseudomyrmex ants, which feed on extrafloral nectaries on the leaf-stalk and small lipid-rich food-bodies at the tips of the leaflets called Beltian bodies. In return the ants add protection to the plant against herbivores Some species of ants will also remove competing plants around the acacia, cutting off the offending plants' leaves with their jaws and ultim,ately killing them. Other associated ant species appear to do nothing to benefit their hosts.