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.
Warm bodies , they have fur to keep them 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.
They have Fur to keep their bodies warm.
Lots of layers help keep bodies warm, and minimizing the time out of doors.
To keep warm of your body
no it helps the fish breathe
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
to keep the cows warm and cover their bodies