Normally, their diet is quite restricted and they only eat eucalyptus leaves. However, there was one that lived at the Sisters of Mercy convent in Sydney. It developed a liking for the tea leaves left in the sisters' cups after they finished afternoon tea. So the sisters insisted in having the leaves left in. And that gave rise to the saying, "The koala-tea of Mercy is not strained,"

no. eucalyptus leaves are the only thing they can eat