I THINK this is a baetidae. Hook size 18 or 20. Olive body. Body between 5 and 6 mm.
Very small (size 26 hook size), dark brown/olive body, 2 tails. Rotund.
Small (6 mm or so), dark brown body, heavily speckled leading edge of wing with was otherwise transparent. 2 tails.
One of the female mayflies on the screen door. See also: http://www.inaturalist.org/observations/859265
One of three on the screen door this morning. This one has large eyes (male). The other two had small eyes (female: http://www.inaturalist.org/observations/859283).
This was probably the smallest mayfly I have ever seen.
Baetidae is a family of mayflies with about 900 described species distributed worldwide. These are among the smallest of mayflies, adults rarely exceeding 10 mm in length excluding the two long slender tails and sometimes much smaller, and members of the family are often referred to as small mayflies or small minnow mayflies. Most species have long oval forewings with very few cross veins (see Comstock-Needham system) but the hindwings are usually very small or even...