I used to feed my o mealworms or morios, earthworms, maibugs, crickets, grasshoppers, maggots and they never refused anything, except for the 2" grasshoppers from the baitshop.
They were a bit too big for my o at the time.
But cricket are a no-go for my Oscars now, after some escaped and kept chirping VERY LOUD ALL NIGHT LONG!!!
VERY ANNOYING and i had a hard time getting rid of them.
My initial idea was to leave to door open at night so the cricket could get out .
Think again, cause in the morning i had 3 of them istead of one that had escaped before.
He lured some others over, instead of getting out of my home and the bunch of them drove me mad! :angry:
Plus my arachnofobic wife does not like the sight of the big crickets running through our home after they escape...
You can pull of some of the crickets legs to keep them from jumping, but that's not my thing.
and no lectures, just some info on thiaminase, to help you make up your mind on feeding goldfish to your Oscar.
www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm