# Praying Mantis egg cases -- Help me breed monsters **URL:** \ **Category:** Factual Questions\ **Created:** [November 2, 2008, 8:14pm UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751 "2008-11-02T20:14:12Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [November 2, 2008, 8:14pm UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/1 "2008-11-02T20:14:12Z")
Last spring, I bought a couple of praying mantis egg cases and, after they hatched, released carnivorous death on my garden pests. While doing yard work today, I discovered a handful of familiar looking egg cases on various stalks in the garden. So I harvested them and put them in a zip lock bag in the refrigerator. What’s the best way to keep the eggs alive and healthy over the winter? Is the refrigerator a good idea or should I just put them in the (fairly cool) cellar? Should I put in some wood shavings to keep the humidity up? Is there anything that lays eggs cases that I might be confusing with those of the praying mantis? (Looks a bit like an oval piece of styrofoam on a stick.) ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 2, 2008, 8:22pm UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/2 "2008-11-02T20:22:14Z")
Why don’t you just leave them outside, where they need to be to do any good anyway? ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [November 2, 2008, 11:09pm UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/3 "2008-11-02T23:09:31Z")
I used to raise praying mantises when I was a kid. You really should have left them where they were. For one thing, you do not want thousands of newly-hatched mantises swarming around inside your house, looking for food. Take it from me, you don’t. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [November 3, 2008, 12:42am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/4 "2008-11-03T00:42:36Z")
> [@panache45](#): > > I used to raise praying mantises when I was a kid. You really should have left them where they were. For one thing, you do not want thousands of newly-hatched mantises swarming around inside your house, looking for food. Take it from me, you don’t. How do I get Gin and Tonic out of my nose? - Need answer fast! 😃 ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [November 3, 2008, 2:51am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/5 "2008-11-03T02:51:46Z")
> [@beowulff](#): > > Why don’t you just leave them outside, where they need to be to do any good anyway? ``` The egg cases were mostly in my wildflower garden that gets mowed down to a couple of inches this time of year. Another one was in some morning glory vines that I was taking down after it got killed by frost. I'm also not completely sure how well mantis eggs handle subzero temperatures, so I'd like to maximize their survival. ``` The egg cases, as I said, are now in a zip lock bag, so swarms of tiny mantids shouldn’t happen. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [November 3, 2008, 2:55am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/6 "2008-11-03T02:55:30Z")
Note that when they hatch, if they are confined, you’ll end up with one Mantis. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 3, 2008, 2:56am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/7 "2008-11-03T02:56:30Z")
> [@Finagle](#): > > The egg cases were mostly in my wildflower garden that gets mowed down to a couple of inches this time of year. Another one was in some morning glory vines that I was taking down after it got killed by frost. I’m also not completely sure how well mantis eggs handle subzero temperatures, so I’d like to maximize their survival. > > The egg cases, as I said, are now in a zip lock bag, so swarms of tiny mantids shouldn’t happen. I think they are perfectly adapted to your environment. I would find a protected place outside and just leave them there. If you have them inside, they may hatch too early (in the middle of winter). Also, if you have them in an enclosed container, and you forget about them, the young mantids will perish. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [November 3, 2008, 3:42am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/8 "2008-11-03T03:42:37Z")
> [@DrDeth](#): > > Note that when they hatch, if they are confined, you’ll end up with one Mantis. If they hatch and they’re confined in a ziploc bag, there’ll be no live ones. Even mantises need oxygen… ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [November 3, 2008, 4:10am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/9 "2008-11-03T04:10:20Z")
The egg cases themselves need some oxygen so keeping them in a ziploc bag probably isn’t a good idea. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [November 3, 2008, 4:43am UTC](https://boards.straightdope.com/t/praying-mantis-egg-cases-help-me-breed-monsters/470751/10 "2008-11-03T04:43:29Z")
When I was in grade school we kept some eggs in the refrigerator. They didn’t hatch until we removed them weeks or months later.