I test smart bird feeders year-round for WIRED. While I love the variety of birds attracted by seed feeders, there’s something to be said for the simplicity of a hummingbird feeder. My favorite hummingbird feeder I’ve tested happens to be on sale right now, the last day of Prime Day—a rare chance to snag it for yourself or as a gift for $53 off. One of my least favorite parts of dealing with hummingbird feeders is having to fill, refill, and clean the reservoir. Bird Buddy is the only smart hummingbird feeder I've tried whose reservoir simply unscrews from the bottom.