I say at instead of on because while the stream of liquid was just that, a stream, it didn't hit me. So I just fed Verde and Boom, and Boom jumped on Verde afterward. Verde let out a bit of a noise, and Boom left a second later, but Verde then shot liquid out of his bottom toward the front of the tank. Just wanna make sure, is this urine/waste/"get off me" response, or do I have something to be concerned about.