Well what happens is, the sound only plays when all wasps are on screen. It doesn't work if only some is visible, or only one for example.
Have been trying to tweak it any way I can, but it hasn't worked so far. Not sure if I'd like to overlay a empty sprite for this, but might resort to it if it works and if there's no other solution.
The layer the Wasps are on, have default parallax.