Yes, that was my impression before I joined this site - that they would hide all the time.
A passerby noticed my largest aquarium through my living room window as it was lit up on dark nights.
As an unsucessful fishkeeper he wanted to give me his two remaining fish, a mature female Krib and a large single Kuhli Loach, so he knocked on my door.
To save these two healthy fish, I took them off his hands and added them to my Clown Loach aquarium.
The Krib proved to be a lovely addition to my aquarium and later bred when I purchased a male. However, I never saw the Kuhli Loach again!
My brother has since kept Kuhli Loaches in a group. They could be seen at any time foraging on the substrate among the dense plants.
6 x Clown Loaches, 1f9", 1f8", 4m6", 1995, 6' x 18" x 18" 90ukgal/110usgal.