For the health and safety of your caterpillars, it's important to be very gentle while they are developing in their cup. Remember, this is first and foremost an observational project. If the cup is excessively carried, shaken, or otherwise disturbed, it can impact your caterpillar's ability to transform into butterflies.
For the best chance of success, keep the cup in a quiet location on a shelf, away from drafts and vents. Do not open the cup and touch the caterpillars, as that can introduce bacteria to the cup. When the caterpillars are turning into chrysalides, it is especially important not to disturb them.
Raising your caterpillars is an exciting time. By being as gentle as possible with your cup you're giving your caterpillars the best chance to mature into butterflies.