As far as I know, you can only determine it to an extent. If they have wings at all (females will have shorter wings, sometimes harder to see, males will generally always extend past the end of their abdomen), they are a full adult, which would indicate anywhere beyond 2 months, depending on species. You can also judge based on size, as they generally double in size each molting. If they are about 1/4 an inch, they are newborn, then they molt each week or so, doubling in size. So if it's about an inch long, they would most likely be 2-4 weeks old.
Praying Mantis
A Praying mantis is a invertebrate
are praying mantis in the bible
The plural of praying mantis is praying mantises or praying mantes. The plural of grasshopper is grasshoppers.
Most species of mantis can fly, including the praying mantis.
The female praying mantis are famous for eating the male after mating.
No a Praying Mantis is harmless to a human.
the praying mantis has ghwrjh4thy42 arms
35a praying mantis can see
no praying mantis do not have eyelids
You do know that a praying mantis is an insect right? The praying mantis isn't actually praying. It is called that for the stance it makes.
No, they reproduce sexually. Some of the species praying mantis can be reproduce asexually. But not all the species of praying mantis asexual.