My husband and I found these while cutting down firewood on our property. We live in Michigan, and these were found on Sept. 18.
They look like they have 6 legs, a white body with a brown/black rear. It also has a fuzzy, cotton looking tail or rear end. They are small, but can be seen with the naked eye. They look like their back tail is dancing when they move. What are these little guys?
The insect your husband found while cutting wood is one of the woolly aphids (subfamily Eriosomatinae). It really looks like the beech blight aphid which can be in your area.
The woolly aphids form large clusters of individuals that are covered with a wax coating and wax feathered secretions…like the tail end of your insect in the photo.
The 4th instar (stage of nymphs)are very active…which is what your insect looks like.
The beech blight aphid feeds on beech. There are several species of woolly aphids. Some only feed on one plant species while others feed on many plants. Though these are aphids they do not have or they are very reduced…the 2 rear appendages called cornicles (on other aphids they look like stovepipes sticking out of either side of the rear end).
Eggs are laid to overwinter. Some of the species form galls on plants when the eggs are laid. If one of the aphids you saw have wings it would be an adult. The adults do not feed, the nymphs suck juices out of the plant host.
These insects do not bite nor cause a rash.