The peacock mantis is one of the most outgoing mantis'. He may be just getting use to your tank. He should eat krill, but mix it up with other frozen fare. Some people think you need to feed live food for them to strengthen their pummels on, but all you need to do is buy empty snail shells and stick frozen food in there. Get a piece of black PVC fitting and make him a nice little u-tube cave. Not being able to molt in complete darkness has been connected with shell rot. Give him lots of rock rubble so they can reorganize everything. I feed on Mon. Wed and Fridays.
