VCAs can be found in any terrain and under almost any circumstances. And regrettably, they can fly. Their vibrations initially are harmless, but if allowed to continue for over 6 minutes (i.e. 360 seconds), everything just starts to feel awful. Scientists are so far not able to explain it. Examples of the awfulness:
 If you are baking a cake and a VCA is undetected in the area, the cake will taste awful.
 If you go to the hairdresser and a VCA is in the vicinity, your hair will look awful.
 If you’re singing in a concert and VCA is somewhere in the room, you will sound awful.