According to Genesis, Noah took one pair of each unclean animal into the Ark.
Genesis 7:2 distinguishes between clean and unclean animals. Noah is instructed to take seven pairs of every clean animal, but one pair—male and female—of each animal that is not clean. Genesis 7:8–9 then describes animals going into the Ark in pairs.
The passage is often remembered simply as “two of every animal,” because the paired male-and-female image is central to popular versions of the story. That summary misses the special numerical distinction made for clean animals. Genesis 7:3 also gives a separate instruction involving birds of the sky.
The category “clean” is not defined in detail within the Ark passage itself. Readers commonly connect it with later biblical dietary classifications, but the text’s immediate point is the different number of animals brought aboard for the two categories.