Heaping insulation over the ducts is fine in dry climates but can cause condensation on the duct insulation jacket in humid climates.
Theres a kink in the attic.
The creaking sound is perfectly normal and is caused by the movement of roof timbers responding to changes in temperature.
The doe s building america program recommends beds buried encapsulated ducts.
There s one caveat to your attic suggestion however.
There are a number of wild critters that could be causing the noises but among the most common are things like squirrels bats rats mice raccoons skunks opossums and birds.
It can ofter sound as if the roof is broken in some way or the roof is going to collapse.
Unwelcome or not it sounds as if there is a wild animal making those scratching sounds in the attic or walls looking for somewhere to rest its head and rear its young.
A clicking air conditioner noise that starts slow and gets faster could come from an obstruction.
Art plumbing ac electric has been performing attic rat removal in florida since 1983.
By spraying closed cell foam on the ducts before burying them in attic.
At night attic can sometime make loud creaking and cracking sounds.
There may be something damaging the blower fan.
Sometimes you will hear a knocking while other times you may notice a scurrying sound thumping noise or something else.
If the unit is making a continuous clicking noise but won t turn on it could be an electrical problem.
Knocking sound in attic if you hear a knocking sound in your attic this is a pretty good indication that an animal of some sort has taken up residence in that space.