Even though bettas can survive in unheated water they prefer heated. They are a very hardy fish which is why people assume they like cold water just as much as warm etc. However unheated water can slow down there metabolism etc and that may be why they are inactive. They are a tropical fish just like all the others, just because they can survive in unheated does not mean they like it. I hope they are a bit more active today, they look nice in the pics.
