Kitten Suckling

My kitten is sulking on my older cats nipples which is not its mother is this normal and will it do the older cat any damage??

it won't harm ur other cat. the kitten was probably taken away from its mother too early.
   
my sister has a cat that sucks on her own tail when she sleeps bc she was taken away to early.

Kitten was taken away from its mother when it was 9 weeks old