Nettles are a herbaceous perennial flowering plant in the family Urticaceae.
It is native to Europe, Asia, northern Africa, and western North America, and introduced elsewhere. It is the best-known member of the nettle genus Urtica.
The species is divided into six subspecies, five of which have many hollow stinging hairs called trichomes on the leaves and stems, which act like hypodermic needles, injecting histamine and other chemicals that produce a stinging sensation when contacted by humans and other animals.
The plant has a long history of use as a source of medicine, food, and fibre.
It grows 1 to 2 m (3 to 7 ft) tall in the summer and dying down to the ground in winter. (source)
So can hamsters eat nettles?
No they cant unfortunately. They will hurt hamsters if they are eaten and so are best avoided.