A bottom gate holds its frozen bait in {TAIL ~ the tunnel} until {HEAD ~ the blades} have sliced the bait into pieces 
A bottom gate holds its frozen bait in { TAIL ~ the tunnel } until { HEAD ~ the blades } have sliced the bait into pieces
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH