rough mat (reeds)
簀 refers to a rough mat made from reeds or bamboo, used for sitting or sleeping.
簀 combines 竹 (bamboo) with 責, which likely contributes a phonetic element. The character originally referred to a bamboo mat.
The top 竹 (bamboo) over 責 suggests a woven bamboo mat. Imagine a rough mat made from bamboo strips, used for sitting or sleeping.
For サク, picture a sack made of rough reed matting: sack -> サク, and the mat is woven from reeds.
fish pen; holding pond; fish tank; live well; live-box
mat (made of pieces of split bamboo or reeds tied together)
the death of a scholar
bamboo screen or blind
drainboard; floor grates; duckboard; slatted wood (e.g. used as a base for storing futons inside a cupboard)
wrapping (something) in a bamboo mat
reed screen