Little insect I'd force to pierce me (5)
I believe the answer is:
midge
'little insect' is the definition.
'midge' can be an answer for 'insect' (midge is a kind of insect). I'm unsure of the 'little' bit.
'i'd force to pierce me' is the wordplay.
'force' becomes 'G' (short for gravity).
'to pierce' is an insertion indicator (some letters pierce a hole in others).
'id'+'g'='idg'
'idg' going inside 'me' is 'MIDGE'.
Can you help me to learn more?
(Other definitions for midge that I've seen before include "Be an obstacle" , "Tiny swarming fly" , "A small biting gnat-like insect" , "Tiny biting fly" , "Minute mosquito-like fly" .)