When a light-sleeper (such as myself, to take a random example) decides not to wear his (or her, but in this case, his) ear plugs on any given night (such as last night), it does have certain benefits. Yet even those benefits may not be considered wholly beneficial.
A story, illustrating my point:
David (a handsome young man in his twenties) was in such a situation not so long ago, and he discovered that the whining of a mosquito coming in for the kill was detectable to his unconscious but un-plugged ears. He would be awoken, thereby saving him from rising in the morning having had all the blood sucked out of him. A benefit, certainly. Yet unfortunately, this particular night was a friday night, and so the mozzies were out-on-the-town (as they call it) in great number, forcing the handsome young man from his bed on at least half a dozen occasions, in order to turn on the light and chase flying insect-demons around the room (to their DOOM). This disturbance in his sleep caused him to only achieve 94% of his usual handsomnity/gorgeousness on the following day, and despite this cost he still managed to get bitten on the hand (twice), the toe, and the neck. A sad story.