Hi. Can anyone remember a children tv programme from the 80s, I don't think it was a cartoon, might have been a puppet thing??

Some creatures lived underground and had a big round door leading outside. When they would leave the safety of their lair some baddies would try to get them and always chase them back to their big wooden door (leading to their underground home). I remember the baddies being a big rat-like. It's not Fraggle rock but probably around a similar time. Thanks!