Mantis babies, or nymphs, do not stay in a cocoon; instead, they hatch from an egg case called an ootheca. The eggs typically take about 3 to 6 weeks to hatch, depending on environmental conditions such as temperature and humidity. Once they hatch, the nymphs emerge fully formed and ready to begin their independent life.
An inchworm will stay in their cocoon for about 2 weeks. They tend to stay in an extra week most of the time.
As long as they stay babies is how long they stay babies.
about ten days
they curl up in there
The Cinnabar Moth will stay in their cocoon for a period of nine months. They cocoon themselves in the early summer and do not emerge from the cocoon until the next spring.
Black Swallowtail butterflies stay in their cocoon for 9 to 11 days.
about ten days
1 week
a month or a little bit more
Probably about ten days.
I do not know the exact answer but most praying mantis live in warm and subtropical areas
Normally if they get lucky just 2 weeks but if not at least a month :)