this is a quote from pythons of the world, volume II Ball Pythons the history, natural history, care and breeding by David and Tracey Barker page 230 "ball python eggs respire as they develop, takin in oxygen and releasing carbon dioxide. ...eggs can be suffocated in a small and airtight egg container if the container is not opened occasionally. ...As soon as an egg slits and the snake inside begins to breathe air, it is necessary that the egg container be ventilated,..."

here is another quote from the above refrenced book this time page 231 "you are creating an enviroment of high humidity, yet at the same time...ball python eggs do not tolorate getting wet. ...they cannot withstand water dripping on them."

it goes on to say that if condensation drips on the eggs pat them dry with a paper towel and as long as it only happens occasionally (like when you open the lid) they can survive.

Some one else said that condensation comes from differing air temps and that is correct. The air out side of the egg container is cooler than the air inside.

I would vent the egg container so that the air in the incubator and the air in th egg container stay close to the same temp.

Just keep an eye on the humidity.

Good Luck!