When Pharoah asked the midwives why they were letting the Jewish boys live, they claimed that “the Hebrew women are not like the Egyptian women, because they are lively [chayot]” (Exodus 1:19). The Talmud (Sotah 11b) explains: “They are being compared to wild animals [chayyot],” which, as Rashi (s.v.) observes, don’t need midwives.
The Talmud goes on to list verses where children of Israel are compared to animals, such as “Judah is a lion’s cub” (Genesis 49:9). I think one could read the same pun on a different level. The midwives are appealing to Pharoah’s ethnic prejudice: “You know those Hebrews. Just like animals, they are.”