Enclosures – all the Equipment you need for invertebrate husbandry.
From my General Mantis Care Sheet –
Praying Mantis Enclosures – Praying Mantis Habitat – where to keep Praying Mantis – for your Mantis to live in:
The general rule is that the height of the habitat/enclosure is 3x the length of the Mantis, and 2x its width. So let’s say your Mantis is around 3-4cm in length, then an enclosure with dimensions of 12-15cm high x 6-10cm wide x 6-10cm deep is perfect, or, for example; anything around half a pint to a pint in size, including 24-32oz Deli pots, or a cricket tub which is also great at this stage too (Figure 1).
Figure 1. Cricket tub enclosure is a simple and adequate enclosure for a small/medium sized Mantis.
You don’t want anything too big as the Mantis won’t see the prey you put in there, and might starve.
If the Mantis is not yet an adult, you need to make sure there is something for the Mantis to hang from in order to moult too. So either a mesh lid, or mesh at the top just under the lid, and/or horizontal twigs/sticks. These sticks/twigs need to be high enough for the moult to occur without the Mantis touching the bottom (hence the 3x body length rule).
For adult Mantids such as this one in Figure 1 (Adult female Otomantis scutigera), the rule of 3x height no longer applies because the Mantis is an adult and as such has no more moults.
With regards to foliage etc…well, it’s up to you. People who have one or two Mantids tend to make their enclosures as aesthetically pleasing as possible. This is purely for our own benefit of course, the Mantis couldn’t care less how pretty it is ha ha….. I suggest the odd piece of foliage as this might make the Mantis feel a bit more ‘at home’, not too much as to make the place look too busy though, and also, if there is too much, then prey will just hide, and your Mantis won’t see it, again, possibly leading to your poor Mantis going hungry.
Also see wikiHow