Insects closer to yellow snakes (5)
I believe the answer is:
wasps
'insects' is the definition.
(wasp is a kind of insect)
'closer to yellow snakes' is the wordplay.
'closer to' suggests the final letters (the letter which ends or closes the word).
'snakes' becomes 'asps' (asp is a kind of snake).
The last letter of 'yellow' is 'w'.
'w'+'asps'='WASPS'
(Other definitions for wasps that I've seen before include "Stinging hymenopterans" , "Rugby club" , "English Protestant stingers?" , "Striped stinging insects" , "Ones playing together" .)