From the East Lake Resort (Oregon) website re flyfishing:

“Early in spring, gases begin filling the void between the exoskeleton and the body within As the pressure builds, the exoskeleton starts to swell and the nymph becomes unnaturally buoyant. The exoskeleton stretches thin and radiates a shimmering glow as light reflects from the taught skin and interior gasses. Perhaps to lessen the uncomfortable pressure, the nymph starts crawling upwards. This isn’t happening to a lone individual, but to hundreds, or perhaps thousands of nymphs at the same time. Up the weeds, up the rocks, up the stumps, and even up the legs of wading anglers these nymphs migrate toward the sun.

When these swelling nymphs lose their footing or try to swim, the buoyancy in the trapped gases lifts them away from familiar surroundings and they desperately swim back down to the protective cover. Soon they will lose footing again and once more be buoyed towards the surface and once again the nymph will struggle back down to cover. To the scuba diver this looks like a beautiful dance as showers of glistening nymphs bob up and down over the weed beds. To the trout it looks like breakfast.”

I placed the emphasis on the bold text and as in previous posts re The Orb and my earlier observations during a Callibaetis hatch on Oregon’s East Lake….just let me say this: the roads are nearly open to the lake, the ice is off and the weather has warmed considerably.  June beckons and if all aligns I will be confirming my suspicions on the worthiness of The Orb.  (The Orb by Gary Muncy).