They* technically can bite you, but the bite doesn't hurt, so it's likely only effective against other really small critters. They can also release some sort of glue, kind of annoying if they do it while tangling in your hair, but harmless.

I wonder if their visual similarity to wasps isn't some form of defence on its own, as mimicry. They also seem to build nests in places where they won't get into trouble with mammals, like inside the hollows of tall trees. And that opening "tube" is closed off at night.

*from some websearch I could find one slightly more dangerous species, called "tataíra" or "abelha de fogo" (lit. fire bee). Even then it's just spitting formic acid, like ants would; and mostly used not against larger critters, but while pillaging beehives of other species.