Took my family to cancun for a weeks vacation, as we were trying to find our room on the resort I heard that oh-so-noticeable CHIRP coming from a stairway.
Tickled my pickle because I couldn't hear it from our room, but made me laugh as multiple times going down that stairwell and coming across someone from hotel staff (house keeping, wait staff, maintenance etc) nearby I asked them if they were going to change the battery in that cause it had been going off for multiple days.
All of them said the same thing, basically "Oh no senor, that is from the birds who nest up there". If I pulled out a stop watch and showed them it went off every 60 seconds on the spot, they probably would have looked at me like I was some sort of wizard.