Little biter (4)
I believe the answer is:
gnat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">little biter</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for gnat that I've seen before include "Insect like small mosquito" , "Two-winged fly" , "Small bloodsucker" , "a little bit of a nuisance" , "Small (swarming) fly" .)