The cat communicates with autistic boy

Four year old Fraser Booth is autistic and has failed to create the usual communication levels of an average four year old until he met Billy the stray cat. Suddenly he was able to display care, concern and love that autistic children find so difficult. When Billy arrived Fraser said ' This is our cat,he can come and live with us.'
and Billy still does!

Who is being nice to whom?

Source : Daily Mail June 16th 2012