A wholly respectable decision Lisa. If you feel that they are not settling to captive life, and the weather and conditions are still good enough for you to release them where they were caught, then that's a completely unselfish thing to do. It's a sad decision to make, but much respect to you for making it.

Just to check - the weather should stay warm enough after you release them back for them to acclimatise, get their bearing and find their way to a den before it turns too cold? I got the sense from what you wrote that it is a case of release them now or it will be too close to winter.