However, it's important to keep these things in mind:
* Moderation is key: Mustard greens are high in oxalates, which can be harmful to hamsters in large quantities. A small piece, about the size of a hamster's nail, is plenty.
* Wash thoroughly: Always wash mustard greens thoroughly to remove any pesticides or dirt.
* Introduce slowly: Like any new food, introduce mustard greens to your hamster gradually. Start with a tiny piece and monitor for any adverse reactions.
* Variety is important: Mustard greens are just one part of a healthy hamster diet. Make sure your hamster gets a variety of fresh vegetables, fruits, and hamster-safe pellets.
If you have any concerns about your hamster's diet, always consult a veterinarian.