Some do not grow wings at all, having "lost" the possibility in the remote past.
Ants have alate queens and males during the mating season and wingless workers, which allows for smaller workers and more populous colonies than comparable winged wasp species.
[1] True flies are insects of the order Diptera.
Most insects of this order have two wings (not counting the halteres, club-like limbs which are homologous to the second pair of wings found on insects of other orders).
Wingless flies are found on some islands and other isolated places.