I really like this birdseed sensory bin that my daughter helped me to make. We filled the sensory bin up with a birdseed mixture, you can find this at Menard's or a similar store. We added in some birds we got from the Dollar Tree, a yellow daisy sink strainer. We also had a little toy nest and a little toy bird bath to use, as well as a butterfly eraser I put in.
It's a very close to nature sensory bin and the kids can use the sink strainer to scoop and pour and play with the bird seed.