Researchers from Free University of Brussels found that cockroaches have “personalities—that is, consistent behaviors, such as boldness, shyness, sociability, or aggressiveness” – just like “a range of invertebrate species, from octopuses to water striders to social spiders” as other researchers had found earlier. And the researchers found “when cockroaches get together, they create a group personality. The group personalities of cockroaches vary, too.”