One way to get rid of a creepy-crawly? Shake a leg (4,2,2)
I believe the answer is:
step on it
I believe this is a double definition.
'one way to get rid of a creepy-crawly?' is the first definition.
(as in stepping on a creepy-crawly to kill it)
'shake a leg' is the second definition.
(I've seen this in another clue)
(Other definitions for step on it that I've seen before include "improve rate of advance" , "to flatten an insect?" , "Go for speed" , "to take advantage of escalating opportunity" , "How might one kill an ant" .)