Aeglidae is the only family within the Infraorder Anomura that successfully invaded continental waters (Bond-Buckup et al. 2008) thereby isolating it from its closest relatives, the marine Anomura. The comparison between Aeglidae and their close marine relatives can enlighten us on the behavioral adaptations needed to invade freshwater environments. And comparing with other freshwater decapods, such as crayfish, can help us to understand convergent behavioral adaptations for freshwater. If we look at both comparisons, we may get a better understanding on how the environment and phylogenetics shape behavior. In this chapter, we will use this scenario as a guideline. First, we establish what is known for aeglids regarding 182mating and fighting behavior, also reviewing how different species of aeglids interact among themselves. Second, we review how aeglids interact with other freshwater decapods. Lastly, we compare the behavior of Aeglidae with that of other Anomura and crayfish. By providing these comparisons within Aegla and among decapod crustaceans, we hope to broaden our current understanding of the evolution of Aeglidae.