what is the size of your snakehead?try to starve him for 2 weeks then try to put a beef heart or pork liver and observe it after 10 mins and the beef heart or pork liver you drop on its tank is not touched..remove it then continue to starve him until it get 1 month for sure your snakehead will eat
When you feed with live feeder throw at the same spot one at a time everyday ,soon it get use to it when food drop it attack it . Starve it a few days throw shrimp meat it works for my snakeheads .
you could try to use a little tread and tie a knot arround the food.
then you drop it into the water ,and if they dont eat it within a hour or so you can remove it , put it in the freezer and try later
works great here