Chances are someone is just being a troll by inviting them.

Kicking them won't really do anything since NN will automatically make you rejoin as soon as your timer is up and with the bots constantly zoning in and out of Amdapor Keep they'll be getting back in the instant their kick timer has expired.

I've personally kicked them before, and as long as you plainly state that they're bots and why you believe that to be the case it's unlikely you'll get in trouble for it.

They'll get banned sooner or later, but this problem will keep repeating until SE starts taking more permanent measures against them.