I live in an apartment building built in 2006 on the first floor. My Master toilet is sensitive and clogs more than any toilet I've ever had. I've changed to single ply toilet paper. Every few months the toilet will start to gurgle/bubble even when we haven't used the toilet. Like last night at 11pm and again this morning at 10am. I have a guest bath that has the same toilet as the Master which never clogs or gurgles. I've had the Master snaked with a 6 ft Ridged auger about 6 times and yet the Master still can't reliably be used for BMs and every few months it will just start gurgling. I think I heard the upstairs neighbor flush this morning and then my Master started to gurgle. I've read that gurgling can be caused by a blockage in the toilet (which I doubt because this toilet is flushing perfectly without any slowness), or the Vent, or a clog farther down the line ever outside the building sometimes. I'm trying to figure out a logical way to diagnose this. The cheapest way is to snake the toilet ($210), or pull the toilet and snake further down the line, check the Vent for animal nests, etc., call the city to check the pipe line. Does anyone have some input on a good way to logically diagnose these clogging and gurgling problems? Thanks so much. Steven