someone keeps stealing my green mandarins

[felinxo]

So I've got this green mandarin that I feed frozen foods, but here's the thing - every time I feed the fish and the mandarin, those cleaner shrimps swoop in and steal all the food. The mandarin freaks out and shoots off, then comes back to eat what's left. It's like they're bullying my mandarin. Any ideas on how to stop this?

already replied on the other thread