kind of insectivorous rodent, mole
鼹 centers on a small burrowing mammal: a mole, specifically a kind of insectivorous rodent that lives underground.
鼹 combines 鼠 (rat/mouse) with 晏, which likely contributes the sound. The character is used for a mole, a rodent-like animal.
The left side 鼠 means rat or mouse, and the right side 晏 looks like a sun over a woman, but think of it as a mole poking its head out of a hole. Together, 鼹 is a mole, a rodent that digs tunnels.
For エン, imagine a mole digging an endless tunnel: the 'en' in 'endless' cues エン, and the mole keeps burrowing.
mole