Hummingbird moths are more plump than hummingbirds, and grow approximately two inches long. The Clearwings are usually a reddish brown/olive color. Like hummingbirds, these moths make humming sounds when they hover around flowers. What makes them unusual is that they have a very long tongue that they keep rolled up under their chin; when they unroll their tongue they can reach nectar inside flowers that many other insects can't.
The females lay their eggs on plants, usually on the underside of the leaves. The caterpillars are green, so they blend in with the foliage. When they are fully-grown they drop to the ground and spin a loose cocoon. The pupa spends the winter well hidden and the adult emerges the following spring. In northern climates there is only one generation per year.
The white garden phlox pictured is 'David.'
Credit for the photography goes to my husband Ange
Credit for the hummingbird moth information: butterflywebsite.com