Maybe they act differently in greenhouses (or maybe because you get them from Texas)
Have you ever had them in your house?
Praying Mantises are so neat. The first time I saw one in my yard, I saw it too late. Mowed over it. I cried.
One thing I found about ladybugs: if they’re hatched in a greenhouse, they will lay eggs there, and keep reproducing for years, reducing the need for flying-in millions more each season.
If they’re imported from somewhere else, they fly away after the food source is exhausted, and because they are carnivorous, will kill and eat each other in the process. They won’t stay and make the house they’re imported into, a new home by laying egg masses.
When homes become infested, it’s because a female has laid a yellow egg mass, and the hatchlings will return and lay their eggs, and the results are overwhelming. Fumigators and specialists need to be called-in, and sometimes the areas where egg masses were laid, need to be physically replaced; attics, eaves, closets, garages etc.
I’ve see that happen numerous times over my 22yrs owning and running a Family Farm Business, to both friends and customers. I usually remove all the insects to my GHs, and they get the repairs done by carpenters, masons etc.
Praying mantids are the same way; carnivorous and will eat each other when the food source runs out and then the remaining will fly away to lay egg cocoons.
One large female became my “girlfriend” for a season, and she used to stay up in my hat’s crown all day, in my office, the fields and in the Jeep on trips to town. I’d feed her raw hanburger, and then take her back into GH-17 every night, where her mate was.
This pic shows them after mating - she’s quite preggers - and she laid the egg mas cocoon on a plant in the GH, ate the male’s head, and she died when the cold weather arrived. They only live one season. She was gentle and affectionate.
http://i1308.photobucket.com/albums/s607/Family_Farm/js_face_zpsea4bd3ae.jpg
