The answer to 'why is my septic tank making gurgling noise' is that a gurgling sound from the septic tank is typically a sign of a blockage or issue with the system. This can be caused by a variety of factors, such as a clogged inlet or outlet pipe, a problem with the septic tank baffles, or an issue with the drain field.
The gurgling sound is often an indication that there is a backup or obstruction in the system, causing wastewater to be pushed back up through the plumbing fixtures in your home. This can be a sign of a more serious problem that requires professional attention.