Hummingbird feeders with a tank made of glass are easier to clean than plastic. Over time, plastic can absorb liquids or cloud, whereas glass will stay clear as long as you keep it clean. Feeders made with glass are also heavier, which helps to prevent tipping and leaking caused by windy conditions and feathered feasters. However, plastic hummingbird feeders may have an edge when it comes to durability. They're much more likely to survive a drop, for example. If you have a squirrel problem, high winds, or otherwise expect your hummingbird feeder to occasionally fall or get knocked to the ground, then you might want to opt for plastic instead.