What are these mud looking strings hanging from my ceiling

bathroom - Strange mud-like formation on ceiling - Home Improvement Stack Exchange

stringy white stuff hanging from closet ceiling. Brown spots are dust caught in the same stuff (I think). : r/whatisthisthing

What Are Termite Mud Tubes, Signs Of Termite Infestation

Can someone tell me what these litter dirt tubes are coming out my basement ceiling are? : r/DIY

Signs of Termites in Drywall, Ceiling, Floor and Bathroom

Can someone tell me what these litter dirt tubes are coming out my basement ceiling are? : r/DIY

USG Eclipse 2 Ft. x 2 Ft. Mineral Fiber Suspended Acoustical Ceiling Panels (12-Count)

What Are These Mud Looking Strings Hanging From My Ceiling?

Termite Ceiling Damage - Termites in Ceilings

Tragedy at Sand Cave (U.S. National Park Service)

On the Job: Building a Small Ceiling Dome

Mud tubes on the ceiling could be a sign of termites