What do you do when they get flu?

[KMG]

how do they get the respiratory infections?. is about bit air, or humidity? they have his bowl of water, and when they are going to change the skin, I increase the humidity. what can I do more?... thanks!

Sounds like your need to start searching and reading.

Yes, a respiratory infection (RI) usually comes from a combination of poor humidity, temperatures, and stagnant air.

The cages should be vented for air flow, the temps should be (air) around 75f and a a hotspot of 85f. That's what I shoot for. Humidity needs to be 45-55% and can be boosted to 70% for a shed.

If you do not have a good thermometer and hygrometer you need one ASAP. RI does not clear up on its own and they will most likely need medication. Without it they have a slim chance of surviving.