Terribilis are some of the most savage eaters I've ever seen. If theyre not eating aggressively its probably stress from the shipping / move. ive seen the, tackle each other for a single fruitfly. They'll eat anything they can get into their mouths. Hydei ff are perfect. My santa Isabel sub adults are about 1/2 to 3/4 of an inch and they're eating them. You're in good shape. Terribilis will actually refuse small food offerings like melanogasters if they're not starving. Once they're fully grown you can treat them to pinhead crickets but don't make it too often or they'll refuse hydei. Cricket feedings are expensive as a regular staple.