Tandemaus and Maushold
Tandemaus | Normal Scarlet: Exhibiting great teamwork, they use their incisors to cut pieces out of any material that might be useful for a nest, then make off with them. Violet: The pair sticks together no matter what. They split any food they find exactly in half and then eat it together.
Maushold | Normal Family of Three Scarlet: They build huge nests with many rooms that are used for different purposes, such as eating and sleeping. Violet: The little one just appeared one day. They all live together like a family, but the relationship between the three is still unclear. Family of Four Scarlet: The two little ones just appeared one day. The group might be a family of related Pokémon, but nobody knows for sure. Violet: The larger pair protects the little ones during battles. When facing strong opponents, the whole group will join the fight.
Gen 9 Pokédex