Did you quarantine them before you added them to the enclosure? If not I would check out lynns amazing thread on it.

http://www.frogforum.net/showthread.php?p=170940

Quarantining the animals allows you to monitor their feeding and overall health. Also, when doing quarantine you may keep them in a smaller ”environment” so to speak. This is very useful with smaller animals that may have trouble hunting in such a large space. The time in quarantine also allows them to have time to grow and get ready for their new viv. If you haven't quarantined I would do so, it will help the frogs be able find their food easier and again, help you get fecal tests and monitor their health

0.0.1 PCf
Soon to come 0.0.4 Phyllobates bicolor