Do they get plenty of hay?
I grow pots of grass for mine, you can get the seeds here and I just put it in their runs
https://www.thehayexperts.com/index.php?cPath=16
The only thing is it takes about three weeks to grow and they eat it in minutes :roll: :lol: So I have loads of pots of grass around the garden :lol: It needs to be introduced slowly though