You don't have to watch them close, they can be safely left to do so on their own. They don't, to the best of my knowledge, start flapping around like Adele's gob and blasting out curiously mid-Atlantic vocalised middle of the everything songs, or for that matter, demonically warbling like they've been possessed by the spirit of Whitney Houston. Imagine that, if Whitney Houston possessed your bog. Actually, I just did. It's a not a good place.