The insects are let loose among other insects (7)
I believe the answer is:
beetles
'the insects' is the definition.
(beetle is a kind of insect)
'let loose among other insects' is the wordplay.
'loose' indicates anagramming the letters (letters are loosened from their original positions).
'among' means one lot of letters goes inside another (inserted letters are placed among others).
'other insects' becomes 'bees' (bee is a kind of insect. I am not sure about the 'other' bit.).
'let' with letters rearranged gives 'etl'.
'etl' going into 'bees' is 'BEETLES'.
'are' is the link.
Can you help me to learn more?
(Other definitions for beetles that I've seen before include "Lets bee turn to insects" , "Four-winged insects" , "Bet eels could turn into insects" .)