our newest addition, RugRat, is a 9-10 month old stray male (neutered 9
days ago) who is currently staying with my mom (who's in her late 80s
and uses a walker). RugRat is beginning to show some tendency to
attack Mom and this morning broke her skin and started her bleeding in
three places on her ankles. (I suspect that when he goes for her, she
responds with yelling and smacking at him, which I think he may see as
rough play, which may explain why the attacks are increasing).

We have two adult spayed females (currently about 12 years old) who we
adopted when eight years ago. They were the first cats we've ever had
who did not -- EVER -- attack skin. Even in playing with them, the
would not bite or claw at people-skin -- neither hands, arms, feet or
ankles. I LOVED that!

How do we train RugRat that human skin is off-limits -- no biting, no
clawing, no attacking?

We were hoping to leave him with my mom until next Monday (after his
Feline AIDs and Leukemia test results are available) or the following
Monday (when his hormone level is down [3 weeks after the castration]),
but I don't want him to get in the habit of attacking hands and ankles
as some sort of enjoyable "play"! Do I need to bring him home now?