{HEAD ~ This biasing force} will return {TAIL ~ the flap portion} into contact with the base once an insect has lifted the flap to enter the trap 
{ HEAD ~ This biasing force } will return { TAIL ~ the flap portion } into contact with the base once an insect has lifted the flap to enter the trap
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH