Yup - hamsters dig up carpets. They want to know what is underneath ha ha. Or maybe they just can't understand why the "soil" is so hard and they can't dig a tunnel in it. It doesn't matter how big the room or the playpen they will chew and dig at the carpet to get out. Coco's suggestion is good. Another thing you could maybe try that will distract your hammy and get them chewing something else is one of these
It's edible so attracts them and it's a hidey place so they like going inside it. Our hamster spent AGES inside one of these in every position imagineable, including upside down, trying to chew the hay off the inside. That was out of the cage. He would ignore the one I put in the cage (other than to use it as a step). But he'd happily spend a long time in his pet carrier with one of these (eg when doing a cage clean) and I used to have him on the sofa with one of these and he'd just stay on the sofa inside it and try and rip it to pieces. I always freeze mine first for a couple of days just to make sure there's nothing living in the hay
https://www.amazon.co.uk/d/j32/Rosew...+cottage+small