Juli - your kids should be fine, as long as they can swim and are not afraid of the water or dark caves. You'll get head lamp bands for your heads, but it can still get dark in a few small areas of the caves. The water, for the most part is shallow and it is low right now so you shouldn't have any worries; just don't let the 6-year old get too far from you as there are areas of really shallow water where one can drag the rocks and hurt one's bum. : ) Also, there are two spots (depending on how far you walk and how many caves you tube)where you'll run into some VERY mild rapids, and your 6 yr. old probably won't be able to keep his tube from hitting the rock wall, but if you have a good guide (Roberto that I mentioned above, is AWESOME) then your guide will know exactly what to do and when!

And yes...100% Deet is fine. We wanted to walk to the the fifth cave (I think most people walk to the third cave) and once we got past the third cave the mosquitos really got heavy. But...with the deet we were absolutely fine. The walk to the fifth cave is a little harder then the first three, but still a great walk, and very do-able and worthwhile!