Genesis 7:2-3, 8-9

Of every clean animal you shall take with you seven pair, the male and his female, and of animals that are not clean, two each the male and his female; [Lev 11:1-13] also of the birds of the air, seven pair, the male and the female, to keep the offspring alive on the surface of the earth.

Of clean animals and animals that are not clean and birds and fowls and everything that crawls on the ground, they came [motivated by God] into the ark with Noah two by two, the male and the female, just as God had commanded Noah.