Lol, they can be gluttonous pigs and may go after anything that could possibly fit in their mouths. Mine would go after my skunk shrimp when I first got it, but leaves it alone now. I discovered by random chance that he absolutely loves crickets. My kid has a leopard gecko and accidentally let a few crickets loose one time. Well one managed to find it's way to the top of my tank and fell in. I saw this happen, but was not able to get it out right away. All the rest of the fish ignored it, but as soon as it dipped below the surface my cardinal shot out of nowhere and gulped it down faster than my lionfish eating ghost shrimp. Curious to this a few days later I tossed in a freeze dried cricket and sure enough he gave the same reaction.
Fish are weird....
