Hi,
The only way that we can help you figure out what might be going on with your collareds is to get more info from you about your setup and about the collareds, themselves.
Are your collareds captive bred or wild caught?
What are your basking surface temperatures and how are you measuring them?
What are your ambient temps in the enclosure and how are you measuring them?
Is there a UVB source in your enclosure?
Do you feed your prey and do you dust the prey with supplements?

