Insect in pants? (3)
I believe the answer is:
ant
'insect' is the definition.
(ant is a kind of insect)
'in pants?' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ANT' is hidden in the letters of 'pants'.
(Other definitions for ant that I've seen before include "One more provident than Grasshopper" , "one living in colonies" , "Worker on the hill" , "Small busy insect" , "Industrious insect" .)