Parakeet dropings sticking?

I just purchased two parakeets on the 26th. Both young and enjoy each other's company. One is slightly smaller, eats less then the larger but other than that seems no different aside from differances in which toy it prefers or the way he likes to sleep as aposed to the other. However his dropings stick everytime.

It looks just like the other's. White/brown, not runny, slightly wet and clumps. while the other ones dropings falls and rolls down my arm, or hand, the others just sticks to his feathers. it isn't blocking the vent and preventing him from going again. just clumps to his feathers. he's just as active as the other, ive tried lifting the feathers and using a wet/warm qtip to get it off, but it just happens again another ten minutes later.

so is this normal? could he just not be lifting his tail feathers causing it to not drop? or is he sick?

and are they suposed to go to the bathroom nearly every 15-20 minutes?