Does it upset fish if you tap the side of the tank?

[TangledInTinsel]

I know nothing about fish beyond my friend has one. Long standing saga. I was going to get her a robotic fish as a joke present, but see that they can actually go in the tank with real fish. They deactivate after about 5 mins and you can reactivate them by either tapping the side of the tank or putting your fingers in the water.

I don't know if the movement of a fish would automatically reactivate them if it's a movement sensor kind of thing. But would e.g. a child tapping on the fish tank distress the fish?

Tapping on the side of the tank does distress fish. They "feel" it rather than hear it and it can spook them. Extra spooky fish can be sent rocketing around the tank in fear and could seriously injure themselves.

I doubt her fish would be delighted with robot fish in there anyway op.