Babies but where have they gone

My smooth newts had babies just before they dissapered. They are in a tank with a sponge filter so they dont get sucked up(they would be awful). I feed them micro baby fish food i have never seen them eat it. They are around 10 weeks old and as i would expect there are not that many. They dissapered for around 2 weeks so i was thinking about buying a heater to get some fire bellied newts but i saw 2 one day so i thought i dont want to kill them so i wont get the newts. The next day they dissapered again. i think they are just too hard to see in all the java moss. When i last saw them they looked so small not really fast at growing.

How long does it take for them to be full size?
Will they be fine with 3 spine sticklebacks?
I am a big fan of carnivours plants. if i put sundew on the land area will the sundew eat them?

Have a read of this article here, I found it very informative :-

Caudata Culture Articles - Raising Juvenile Newts

What is the fish micro food that you where feeding ? You will not need a heater while raising larvae.

Do not add anything else to their set up, stickleback will find them very tasty.

Its a hakro (i cant spell it) product i think.

Normal behaviour for L. vulagis is to hide among vegetation. Have a look at night as you may see them then. Although larvae should really be juveniles by around 10 weeks. What's in the food? They feed on zooplankton in the wild so diet needs to mimic this.

Oh and absolutely no sticklebacks!

The babies are not eating the fish food. They are eating tiny live invertebrates that hang out in the java moss. To reach a decent size before they metamorphose, they need other, larger live foods like daphnia or tubifex worms.

Is the tank 100% escape-proof? No tiny cracks where a newt could climb out? They are excellent climbers and escape artists. See
Caudata Culture Articles - Preventing Escape

i will get some live food then. never fed that before only meal worms.

the tank is escape proof now. its a old fish tank no cracks the lid is on orignally it was open but i lost a newts so it now has a lid. i dont know what they are doing as there are less snail eggs now could they be eating those.