Most fish can't regulate their body temperature and will simply be (very close to) the temperature of the surrounding water.
Some sharks can maintain an internal temperature a little higher than ambient water temperature.
The fur on their bodies keep them warm.
Ants (and all insects) are cold blooded so they don't keep their bodies warm.
They do not HAVE to be warm. I keep mine under a light built into the lid to keep him warm. It is nice to keep your fish warm. It is very pleasant in winter. I would suggest a warmer.
Warm bodies , they have fur to keep them warm.
They have Fur to keep their bodies warm.
no it helps the fish breathe
Lots of layers help keep bodies warm, and minimizing the time out of doors.
To keep warm of your body
keeping warm
In all probability, when these fibres were made into clothing designed to keep bodies warm: yes.
No because they have short stocky bodies to keep them warm
yes it is because if you have fish in there you need to keep it luke-warm not warm. yes sthere is a difference.. but if you put warm water in there there is a possibility that they could die.. if there are no fish in there be my guest and put warm water in there lol