What are the small white insects I find on the Mulberries in my backyard

I live in Maryland, and have a Mulberry tree in my backyard. Every spring and summer the tree fills up with ripe mulberries, and, while optimally you should wash them, I occasionally just grab a few and eat them right off the tree the old fashion way. However, sometimes I observe small white (kind of a pale manila folder color, much like the unripened mulberries) insect on the mulberries, both the ripe and unripened. They don't seem to burrow inside the mulberries, and are about the size of the seeds that can be seen on the outside of the individual mulberries, maybe a little larger (and I can observe them moving my their own device, so I know they're not just seeds) I'm no entomologist (professional in the study of insects) but they seem like they MAY be the larval state of another larger insect.

However, seeing as most insects in Maryland are harmless, it never really phases me, and I ignore them and eat it anyway, resulting in no adverse affects on my health. Really, I'm just curious.

Sounds like aphids.