These're cat toys.Japanese have called them "NEKO-JARASHI" (the translated name is "playing tools with cat" or "frolicsome tools with cat").
There is a verb "JARERU" in Japan.
JARERU means play, frolic and flirt.
"JARASU" is a conjugated verb of "JARERU".
JARERU is an intransitive verb.
JARASU is a transitive verb.
And, "JARASHI" is a noun.
Do you think that these toys are very similar to an ear of rice or green bristle grass, don't you?