Eagle ray at Hawaii. The playful curiosity of this eagle ray reminded me of a story from the inventor of the <a href="https://www.flickr.com/search/?q=deepflight&w=44124348109@N01&s=int">Deepflight</a> “flying submarine.” On an early test dive, he found himself dancing with a curious eagle ray.... Moving like they do might be a signal of kinship... and may help express universal gestures for play...

Which reminds me of Dr. Stuart Brown, the founder of the Institute for Play, who has a fascinating series of photos of animals playing (ravens sliding on their backs down an icy slope, monkeys rolling snowballs and playing leapfrog, and various inter-species games). “Warm-blooded animals play; fish and reptiles do not.”