Aquatic Ommatotriton

Since i don´t mist the ophryticus tank, i decided to put a small water plate for a couple of hours for them...just in case they wanted to drink or anything... i dunno...it sounds rather stupid right now hehe but anyway i thought i´d let them choose. The thing is...the bigger juvenile was in the water 15 minutes after i put it. It´s been there for around 2 hours now. It´s skin is "aquatic" like. I´ve removed it from the water a couple of times and it has returned. What´s happening here? I mean...it´s only 5.5 cm long, and there´s no sign of sexual differenciation. I think i read somewhere this species might breed(or become aquatic, can´t remember) for the first time at a young age and short size..i think it said about 7-8 cm. Anyone ever saw a juvenile this small go for water so madly? xD
I´m keeping a very close eye on it to make sure it doesn´t drown. Should i remove the water?

Striaight off I'll admit that I have no exp with this species. That said, he would not be in the water if he did not want to be. Short of a suicide attempt there must be something pulling / driving him to the water. It could be hormones, low humidity, or just an intrepid nature but he seems to be interested so I would keep the water there. My granulosas started off 95% terrestrial and in response to their constant pile-up in the water dish I increased their water gradially till they are now 95% aquatic. They have never been happier. They exibit mating behaviour on a regular basis though sadly they have never reproduced.