So I put the hive top feeder on today with some syrup in anticipation of medicating them this weekend...what I didn't know was that during the winter, the top cover must've warped a little bit. I checked on them late this afternoon and found about 100-150 drowned bees. I guess they had crawled in between the exterior of the upper super and the warped lid. Really bummed me out.
I'm going into my second year in beekeeping and just thought I'd share this bit of info so it doesn't happen to anybody else. I'm going to buffer the edges of the top cover so it won't happen again, and then remove that when I remove the feeder. Lesson learned, but it was just a drag.