i use kitty litter for their toilet, and newspaper for their bedding, is that ok, and i usually make pasta and cooked veggies for their dinner, has that got enough nutrients in it, and also i buy a rat mix called rat and mouse dry mix, is that ok. i also give them a water bottle and a bowl of water, i give them cardboard boxes for them to sleep in, whenever i give my rats different food they never seem to eat it all so then all the ants come and sworm their cage. why is this?