The Wingless protein is called "wingless" because of the phenotype of some "wingless" fly mutants. The Wingless protein is called "wingless" because of the phenotype of some "wingless" mutants. They form bands of wingless nymphs which later become swarms of winged adults. The petioles are short, almost wingless or slightly winged. Besides differences between sexual and parthenogenetic morphs, winged and wingless morphs exist. Both winged and wingless forms may be seen. The eggs hatch into nymphs that resemble small, wingless adults. Velvet ants look like large ants, but are wingless female wasps. Immature cockroaches resemble adults except they are wingless. There are many species of wingless moths. Petioles are usually wingless or with minor wings. Like other species in Apterygota, silverfish are completely wingless. They are wingless and eyeless, as are many other ectoparasites. Females are wingless and males have wings. A nymph passes through several immature stages, called instars, all of which are wingless.