"Why does the Torah say, ‘Vayyitzer [And Gd created],’ with two yuds? Because Gd
created humans with two yitzrim [natures], the yetzer tov and yetzer
ra.
"Rabbi Nachman bar Yitzchak asked: If so, then will you
say that animals do not have a yetzer, since for them the Torah says Vayyitzer
with only one yud? But we see that they damage and bite and kick!..."
(Talmud, Berachot 61a)
Have a great day,
Mordechai