This is an interesting question. Though it's not really an answer to that specific question, Jerome Siegel in one paper says: "although animals in the wild are

This is an interesting question. Though it's not really an answer to that specific question, Jerome Siegel in one paper says: "although animals in the wild are usually healthier that those confined to laboratories and zoos, animals in the wild often have less sleep that those in zoos. Sloths in the lab average 15 h/day of sleep, but they sleep 9 h/day in the wild. Frigate birds in cages sleep 9.3 h, but when flying over the ocean for 10 day periods they sleep 0.7 h/day, without rebound. Fur seals have 80 min of REM sleep/day on land, but in water, where they spend >70% of their life, they average 3 min of REM a day. They have no REM “rebound” when they return to land." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8180237/pdf/nihms-1708758.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8180237/pdf/nih... We need to put soft mattresses out in nature and document what happens.