Complex sentence: Workers living in monogyne societies tend to be extremely aggressive and attack intruders from neighbouring nests, and in queenless colonies, the addition of alien queens or workers does not increase aggression among the population.
Split into simpler sentences: Workers living inmonogyne societies tend to be extremely aggressive and attack intruders from neighbouring nests. In queenless colonies, the addition of alien queens or workers does not increase aggression among the population.