My dad used to feed his arowana cockroach & small fish.

The dragon do enjoy insect very much.
but u need to cut off the ulat teeth before u put it in,
then arowana will try to drown it in its mouth by swim deep to the bottom for few minutes, & wait until the ulat no more response only eat it.
sumtime the ulat will use it leg to struggle the arowana eye & face, the arowana will try fing it away, the progress will took around 2 minutes.