Someone who attempts to include themselves in a conversation or group gathering with the disapproval of the other group members.
A scrape can be notified of their scraping through the use of the words "scrape out"

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.

When someone rats in on something they aren't involved in or asked about.