shota tsukasa canonically ate ants because he was stashing sweets (his parents kept him sugar-free usually so he only got dessert on special occasions and wanted to savour it for as long as possible) and those ants ate his sweets so he thought the ants would also taste sweet. he now has a severe fear of bugs and used to faint at the sight of them, much like jamil the very demure and mindful twisted wonderland character