In this case, as with that of the Molothrus or cuckoo, I can see no difficulty in natural selection making an occasional habit permanent, if of advantage to the species, and if the insect whose nest and stored food are feloniously appropriated, be not thus exterminated.
Kasu honetan, Molothrus eta kukuarenean bezala, ez diot zailtasunik ikusten hautespen naturalak noizbehinkako ohitura bat iraunkor bilakarazteari, baldin hori espeziearentzat abantailatsu bada eta, era horretan, habia eta bilduriko janaria traizioz lapurtzen zaion intsektua suntsitzen ez bada.