What laws apply to the housing of hamsters?

Certain legal regulations must be observed when keeping hamsters to ensure their welfare:
Hiding places provide retreats for safety.
A burrow layer of at least 15 cm allows natural burrowing behaviour.
Climbing facilities (be careful not to build above a drop height of 10 cm)
Nesting material supports the need for a cosy place to sleep.
Nibbling objects such as softwood or fresh branches are important for tooth abrasion and activity.