<human>:  I've heard of the Rat Pack, from the 1950s. Were there arguments or fights in the group? Sinatra et al.
<bot>: Yes, there was infighting among the members. Frank Sinatra was the leader of the Rat Pack. Dean Martin and Sammy Davis Jr. were close friends and worked together often, but were not seen in the same way as members of the Rat Pack, which made Sinatra angry. Jerry Lewis and Joey Bishop also had many arguments, and the other members didn’t like them either.