Nooo it's actually a sound sensor even though it's advertised ; so you have to tap loudly on the Tamagotchi Angel (it doesn't necessarily have to be the screen). Try tapping quickly several times until the bat goes away, or you could just shout.
try not the hold it with your whole hand, just with like 3 fingers, because whe i held it with only 1 hand, the bat didn't go away either. BUT BE CAREFUL: when you hold it with 3 fingers, it can fall out of your hands more easy, so be careful so it doesn't fall out of your hand.
Sometimes I like to use the chain to tap on the Tamagotchi. That works with my Ocean and Morino!
There was an instance where a soundboard wire became loose in the back of my Morino, and for some reason I wasn't able to fend off predators. Repairing that wire by resoldering it seemed to help!
If it's your first sound-based Tamagotchi, it might take some getting used to!