When to cut?

[Foschi Exotic Serpents]

this question might be stupid for ball python vets, but i would just like to know why is there a need to cut eggs?tnx.

It isn't required. Most people simply do after the first baby cuts it's egg to ensure all of the others are OK.

It is uncommon but not unheard of for a baby to loose it's egg tooth before being able to pip it's egg. If this happens, the baby can die in the egg. Cutting a small slit also allows you to see if any babies have the umbilical cord wrapped around their body.