buffalo gnat buffalo gnat /ˈbʌfəloʊ ɡnæt/

noun

1. Small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals  ( black fly , blackfly , buffalo gnat )
   small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals