Oh my , what cuteness-overload is this !!! They look like twins !!

A question about those nail caps : how long do they stay on the nails ? Doesn't your cat try to bite them off ?? I don't know if those are available here . It would be kind of handy for my "play-devil" Inka ... ... Sometimes , my hand have so many scars , that people ask me "You have a naughty cat mam?"