I have two male standard imis that grew up together from young froglets, they are now about two years old. Never had any problems with them. I wanted them to have a female so recently i beefed up on the film canisters and made a few pods for laying and rearing sites all together like 8 artificial sites coupled with the broms in the tank. I hoped the multitude of laying spots would keep them from getting aggressive. Yesterday i introduced a female to their 20g vert. I know how imis can be so i watched them real close for signs of aggression. At first they only seemed interested in her, and boy were they interested. They followed her around non stop calling their fool heads off for like three hours before lights out. I actually wondered for a min because i heard so many calls if she was a he. That was how it was last night and early today. This afternoon when i got home the mood was different. One was stalking the other by calls. He would call and when the other did he would hop him down call by call. I saw twice that they would actually wrap up and wrestle. The second time i opened the tank and grabbed at them to separate, they did not even see me coming or did not care. I put the one i caught in a new tank i have been planting and acclimating and boy was he pissed. He stared right at me, i could see it in his eyes. And he should be, I grabbed the alpha, the chaser not the chased. He had that piece won lol. Just another example that imitators males, even ones that grew up together will fight in smaller tanks when females are present. Monogamous frogs gotta love it, the article was right.