Guinea pigs simply adore snug hidey holes, as they use whatever they find in the wild for protection.
I've just bought a small dog bed and covered it with half of an old bath towel, then pegged the other half over it to make a big nest - there is always a queue for my long-suffering, and now sadly fraying little felt basket with an equally fraying kitchen towel pegged to the top (unfortunately, I've never found another one). The loser is quite often sleeping just outside...
I've also turned the purple cardboard boxes from "suet feast" birdfood blocs to good use. They are just the right size and much beloved! Not just for sleeping, but one can push them round, gnaw and generally vent some feelings on them...
When my piggies are bickering a lot, I sometimes throw an old bath towel on the ground, stick a tube between layers, and let them get on with the fun. Or I put the laundry basket upside down on the towel and stick a tube under the edge, and a handful of grass inside. It takes some a bit of effort to figure out the entrance...
In my standard plasitc rabbit cage, I've got a wooden hut and a platform to feed on (and sleep under). We added a ramp after a guinea pig turned blind, but they can jump up quite fine!
p
