Question: C. Orientalis won't eat/get in the water?

Hey guys,
I've been keeping two (male, I believe, but I'm not 100%) C. Orientalis since April of last year, and I've had very few problems.
I moved away to college about two weeks ago and left them in sister's care. She's been taking care of them with me for the last several weeks, so I felt comfortable with her doing uptake while I was gone. She called me last night to let me know that the food she's been putting in had not been eaten, and had been sitting in the tank for a day already. I asked her if they've been spending very much time in the water, and she told me they've been spending hardly any time in the water. This is not wholly unexpected, since my newts are relatively fond of land, but they always go back in the water to eat, and spend about 1/3 of their time swimming in general.
I asked her to replace the food with fresh food, just to see if they hadn't noticed it.
They still aren't eating a two days later, and I'm not sure what to do.
Their tank is clean and full, and I feed them frozen bloodworms.
Should I maybe switch to live food and see if that helps?
Any suggestions would be greatly appreciated. I'm no expert at this, and I'm not super sure what's going on.
Thank you!

Hello friend:
***** Try with nightcrawlers (especially small ones), the movement of the worm is irresistible for newt´s hunter instinct, and it can give even in ground. Rinse well before placing.
***** Check the temperature of the water as if it is very warm, newts prefer to go to the ground. Anyway almost all chinese firebelly newts prefer to spend some time on land so you may not force to be on the water.
***** Good Luck!