Pro Shrimp's comment: Shrimp need places to hide or feel secure from predators. Shrimp Tubes are the most popular hide for shrimp. They are very decorative. You can easily bind some moss on top, making for a great natural look
These Tubes are massive and are great for crayfish as well!
Decorative element for nano aquaria
NanoDecor Crusta Tubes - 3 tubes, large
Ceramic tubes for shrimps and crabs
Water-neutral - safe for shrimps,crabs, etc.
Provide a safe hiding place andreduces stress
Encourage natural behaviour
With bio-filter function: Special porous ceramic material promotes colonisation by filtering bacteria for improved water quality
TIP: Mosses, e.g. Java moss, can be attached for a particularly natural effect