Question about green tree python.

I have a question about a green tree python i have.  i have 2 juvenilles... one is very heatly and moves good and eats great.

 the next one i have is a little odd.  seems... a little weak.  when i spreay the tank with water... it  moves.. and falls off the perch... almost like it has no strength.    it eats.. but harder to make eat.  just in gernal acts wierd.   

anyone have any experience with  a tree pything that falls of its perch.. and seem a alittle weak and almost discorentiented?

 hi probably pneumonia stop misting and rise the temperature,its a big differnce in high humidity and a wet terrarium,does the snake gasp frekvently or lies with its mouth open?Temp and so on mvh kobbe

no it doesnt breath wierd or do anything funny with its mouth.   its just lazy.. i have notices the temps can get quite low at night now so i will work on that