EFT Firebelly Newts-few questions

[Hockeyrooster]

Our newts are now 6-8 months old and growing. They are in a terrestrial aquarium and have found a cave to live in. They are in this cave 100% of the day time and must come out at night to eat. I only believe/know this because they are still alive and growing. I did see them eat a few months ago and it was really cool to see this tiny firebelly chewing on a tiny fly. They have had a staple of tiny fruit flies since it’s the only thing I can find near me that’s small enough for them to eat.
Now for the questions.
1. Should I add a heat mat? I know these are cool weather creatures but I think they are cold. Hear me out. I live in northern Canada and it was -23 Celsius today before the wind chill. The tank sits on an exterior wall about 6” off the wall. The last few times I’ve turned the tank around to check on the newts they have been stacked on top of each other ( and they can not be mating because they haven’t finished their life cycle).
2. what else can I feed these newts? I couldn’t keep grindal worms alive and the newts didn’t care for them. I found 1 week old crickets-can they eat these? Will they eat springtails or Isopods?

thanks!

 

[minorhero]

Is there a reason you are keeping them out of water? I would have figured them to be pretty aquatic critters. You might want to at least put a water dish in there and see if they take to it.

Temperatures are not too cold, that is for certain.

 

[Hockeyrooster]

Hi. The reason I am keeping them out of water is due to them being in a terrestrial phase. There is a bowl with water in the tank they can go in.
here’s some info on how I got to this place:

New Newt Tank-UPDATE Sept 7. another new tank

So these two little guys finally lost their external gills and have been spending a lot of time out of the water. We moved them into this tank a couple of weeks ago. I moved some rocks, the two filter sponges I had floating in the old tank and all of the water into the new tank. At first the...

www.caudata.org

 

[AuSu]

Hi!
If you'fe having them indoors, it can't be too cold. Here in Finland it's now somewhere between -15-20 Celsius here in southwest and our newts are in a room about +12 C. I think it's easier to keep them healthy and happy while winter season, they don't mind getting a cooler period. With heat mat you could do harm and get them too warm or dry, which is a death sentence for them.
You could give them small isopods, I use the white ones and fruit flies. Springtails might be too small already? And if you can find tiny earth worms somewhere but I guess that's not possible in winter. Things that are soft and about the size of their mouth/head. Young crickets can be ok if they don't have the hard body yet - and if they don't bite too bad!

 

[Hockeyrooster]

Thanks AuSu! I have not put a heat mat in and thanks for confirming. I will get some small isopods and springtails only because they are available.
appreciate the reply, thanks!