I only gut rabbits but when i fed them i open up the back passage and rib cage and often just get the thigh bones and a bit of fur out with pheasants i freeze them whole and just split them down the breast bone and just get the wings and legs out the ferret cages
Been popping a few off on the lamp since before xmas there great feeding for a single ferret , i seen to see none then a fair few and when it goes frosty you see none for a bit