Aggressive behavior may play a role in resource partitioning in two Eniwetok stomatopods Gonodactylus incipiens and Haptosquilla glyptocercus. These animals inhabit cavities in coral rubble which they defend vigorously. H. glyptocercus is the more aggressive species and is more than twice as abundant as G. incipiens in the habitat studied. The latter attains larger sizes and also occurs in habitats where H. glyptocercus is rare or absent. A third rarer species, G. falcatus, is also less aggressive than H. glyptocercus and is found in a different microhabitat.