It hears the sound of the tapping on the wall, and turns its focus towards that point, taking a few steps closer to it. However, getting closer seems to cause it to catch her scent more clearly, as it's tentacle-feelers start pointing in her direction more keenly. It lets out of low, almost groaning call, "rrRrrRRrroooooOoooOOOooo," as it probes the air near her, seeking confirmation of her presence.