I've been using Duolingo for many years and before both children and kids were correct for all the sentences. So I always typed "kids" just because it's shorter. Now out of nowhere I keep getting this mistake
The "dormant" applied to volcanos and the French verb for sleep come from the same Latin source. It is very natural to connect the two. That volcano over there is not extinct; it is only sleeping and might very well awake in the future.