The reason is simple.. cats are blind in a certain colour.. by
climbing to these trees, they look up and they can spot this
shining and very attractive colour from afar.. so they will climb
up when they are attracted by this thing..but when they are near to
that colour, the colour will fade as it is located far behind the
cat’s mind. thus, on the ground be it grass or concrete.. that
colour could not be found.. thus, they do not know how to get down…
that colour helps to soothe the cats nerves when they climb
up..
