Have they definitely not come out and eaten any food?
Are you still seeing fresh poops in there?
It can take them a while settle in, they look a bit scared in the picture. Have you covered the entire cage roof with a blanket to make them feel safer?
The issue is piggies need hay constantly going through their system and without eating anything, they can quickly get into medical trouble.
As I said yesterday, the only way to know whether they are in fact eating enough is to weigh them to check their weight is going up. Hay is the biggest part of their diet but you can’t judge their intake by eye, you have to weigh the piggies.