On Betazed, women used to wear huge wigs that incorporated cages for tiny animals. These cages were kept in large holes in the middle of the wigs. This fashion was very cruel for the animals and was abolished after many years as a result of one woman's defiance. (TNG: "Half a Life")
A symbolic cage was referenced in the final draft script of TOS: "Miri", as a classroom full of Onlies surrounding Kirk was likened to a cage containing "too many" lions and a lion tamer.