her. Another way is to remain still while the male mounts, but move her abdomen to prevent the male's genitalia entering her body. Females are also known to mate with multiple males, especially with non-nest mates. They fly over to different males' nests to assess the best-quality males and generally copulate with the resident males. That males are resident males often implies that they are large, sexually active and aggressive – providing better protection for her and the brood. Transitive reasoning P. dominula is the first invertebrate to show the ability to perform the mental operation of transitive inference. This is the ability to deduce that if Tom is taller than Alice and Alice is taller than Pat, Tom must be taller than Pat. This mental ability is common in vertebrates. P. dominula were trained on five pairs in a series one of which (marked s) shocked the insect while the other did not. The series of shocks ran thus: As—B, Bs—C, Cs—D, Ds—E. When tested against a pair they were not trained on, Bs—D, the P. dominula wasps chose D more often than chance, indicating that they had used transitive inference to organize the four pairs into a series, and used that to choose when faced with a pair not seen before. Parasitoidism P. dominula nests have resident brood parasites and parasitoids, including predacious Lepidoptera larvae, Hymenoptera, Diptera, and Strepsiptera. P. dominula is also parasitized by Polistes sulcifer, a permanent workerless social parasite. P. sulcifer females take over the host colony by eliminating dominant foundresses and matching their cuticular profiles. P. sulcifer females gain these cuticular profiles by intensively grooming and licking the host foundresses and workers, or from the nest material which is covered in cuticular hydrocarbons essential for nest mate recognition. This chemical mimicry allows foreign P. sulcifer females to gain acceptance from the host insects. The first well-documented case of parasitoidism of the North American invasive population was reported in 2010. P. dominula are also often infected by Xenos vesparum, a permanent entomophagous endoparasite. Industrial use of salivary proteins Salivary proteins harvested from the nest of P. dominula have been cloned for use as a waterproof coating used in the manufacture of biodegradable drones. The lightweight material used to construct the body of the UAV consists of fungal mycelium covered with bacterial cellulose sheets. The cellulose is then waterproofed with a coating of the cloned protein,