Locally gathered sprays/grasses/seeds?

I was out walking my dogs last night and noticed a big field of tall grass that has gone to seed. Can I gather that and put it in my hamster's enclosure as sprays?

Also, can I gather clover outside? How about chive seeds? I have garlic and onion chives in my garden that have gone to seed. Can I gather them for the hamster too?

And one last question, I saw on a UK hamster page that spider plants are ok for hamsters. Can I put a potted spider plant in the enclosure? I have SO many baby spider plants to pot up and I can definitely share with Waffles. :)

Thanks so much!