You may be interested to know that once you have moist or wet insulation, it may never dry out!
A study in the USA did a test to see how long it would take for wet insulation to dry out in the sun, and depending on the thickness and absorbancy of the insulation type, it takes somewhere between 10-100 years!
For insulation to accumulate moisture, it usually needs to be penetrated somehow for the water/moisture to gain access. Sometimes this penetration can happen in the most unexpected of ways… like being chewed by rodents! Here’s a photo of rat chewed insulation behind the walls.