Female ruby-throat seems to really like this little clip-on feeder

[Walleye]

I think it’s because she gets a good 360° view to watch for intruders

[Donkees]

1. The downside of these tiny feeders is that they quickly ferment as they warm

People often don’t realize that hummingbird nectar begins to ferment once you place it outside. It spoils even quicker when it becomes contaminated...the nectar gets contaminated when a hummingbird takes a sip, even in a clean container.

https://birdsphere.com/how-long-does-hummingbird-nectar-last/

[Walleye]

2. I do wash and refill them quite often. Every day

[Donkees]

3. It's more of a concern as the weather warms. The red plastic absorbs more heat than a clear one ...

I hang the clear ones in the shade, and have rain-guard covers as extra shading for those in part-shade. Still, I switch out the feeders daily, as you do. Information is for anyone considering these tiny feeders.

[Walleye]

4. True, we haven't had any hot weather here yet but I am careful and refill often when it's hot