Rabbi Azarya said in the name of Rabbi Yehuda bar Simon:26Returning to the question of why the animals were destroyed by the Flood along with mankind. They all corrupted their actions in the generation of the Flood – the dog would consort with the wolf, and the chicken would consort with the peacock. That is what is written: “As all flesh has corrupted [its path upon the earth]” (Genesis 6:12). It is not written, “all of mankind had corrupted,” but rather, “as all flesh had corrupted.” Rabbi Luleyani bar Tavrin said in the name of Rabbi Yitzḥak: The earth itself also strayed; people would sow wheat and it would produce darnel.27Which is unfit for consumption. This darnel that grows [today], its origins are with the generation of the Flood.
Even the Animals Sinned Before the Flood
Bereshit Rabbah 28:8