The Effects of Gravity on Photons

We know that photons, for example, do bend to the effects of gravity. We don't really understand exactly how that works because they're quantum particles. And we don't have a theory of quantum gravity. Sounds like you know they feel gravity just haven't tried to figure out how it works. Oh, we'd love to. But those experiments are really hard to do, right? Because the force of gravity from an electron is tiny. The smallest things we've ever been able to measure gravity for are down the size of millimeters.