I have a custom made cabinet that my heating and cooling unit is in.
The heating and cooling component is separated by two different parts in the cabinet, and it has a door for easy access to the HVAC unit for myself and HVAC professionals.
Anyways, well I guess left the door open for a bit too long, because when I was out getting the mail, I noticed a bird landed in my HVAC system and disappeared somewhere. I came closer to inspect, and I noticed that two birds had made a nest out of an HVAC cabinet. Thankfully the area they chose was the area that was separated away from the actual furnace and A/C, so my HVAC component would be okay and the birds would be too. Usually I would just shoo the birds away, but they already had eggs, and I didn’t want to risk scaring them away and killing potential life. So I decided since they weren’t harming anything to just leave them there. Thankfully since birds grow really fast, the babies were there for only a little over a month, before they became fledglings and took flight. After the birds successfully cleared out, I removed the old nest and cleaned the inside of my HVAC machine and then shut the door to prevent them from coming back. I actually still see the same birds every now and then, some of them now with their own families, and I am glad I made the decision to leave them alone rather than remove them.