Watching hummingbird feeders are great fun. It you responsibility to provide them with nectar without dyes and the best way to do that is to make your own. You also need to keep your feeder clean. These are great instructions on how to do it. Temperatures in Celsius 70-84F is 21-29C; 85-87F is 29-30C; and 88-99F is 31-37C.
This also applies to Oriole feeders
-Special feeders like the Aspects' HummZinger Hummingbird Feeder come with a moat that holds water and the ants cannot get to the feeding ports.
-separate water moats are great, they work with all feeders, stopping ants from getting to the feeding ports and providing water for small birds. They are available at Lee Valley Tools.
-these great device will not harm birds, but will catch wasps that often block the ports n hummingbird and oriole feeders. They are available at Lee Valley Tools.