Small biting insect (5)
I believe the answer is:
midge
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">small biting insect</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for midge that I've seen before include "Small biting fly" , "Be an obstacle" , "Two-winged fly" , "Gnat" , "Minute mosquito-like fly" .)