They burrow into moist soil and come out at dawn and dusk when dew moistens everything at ground level. They become highly active in rain. Thoroughly mist the terrarium every day. Your turtle is likely to be most eager to eat right after being misted. Keeping potted plants in the terrarium will offer a comforting natural look, and also help maintain high humidity.
Box turtles enjoy wading and soaking in water, so provide some sort of pool.
They will often defecate in their water container, and that helps keep the enclosure clean, if the water is replaced daily. Box turtles kept indoors should be placed in water to soak every day. Most box turtles are clumsy swimmers, but many of them do seem to enjoy it if a deeper pond is available in an outdoor enclosure. Some box turtles will swim in an outdoor pond for over an hour almost every warm day. Others just wade and soak in the shallow end.