Happy almost birthday i hope you have the best week!!
Rusty is exhibiting "Bullying".
Bullying is undesirable, forceful conduct among school matured youngsters that includes a genuine or saw control irregularity. The conduct is rehashed, or can possibly be rehashed, after some time. The two children who are tormented and who spook others may have genuine, enduring issues.
Im guessing that they had a hard time ratifying the consitution thats what lead to difficulty with the declaration of independence hope this helps
Maybe try to give them both treats to make them happier and your chihuahua has to at some point get along with your kitten. Try to get them to be alone maybe or let them get used to eachother.