Area 51! I like that. I dont understand why it's id would be so secret. Is it a mutant? An experiment gone wrong?
That would be a story to tell, government experiment gone wrong on the mantids, or a extraterrestrial space species
In reality it is much more mundane and is as follows...
In all likelihood the owner of the mantis imported it direct from outside of the country (likely somewhere in Asia) so they don't want to talk about it, to prevent the so called
bug police (APHIS, DNR, USDA, etc.) from knocking on their door with a kill order, large fine, and whatever else they have planned; however, as it was imported it also can fall to other agencies as well.
As the mantid seems to be a relatively, if not completely unknown, species it would really perk their interest too and they would likely slap extra fines/jail time as the user is starting a new species in the country and can hold them responsible for more "wrong doing".
That said though even having anything beyond a native/naturalized mantis is illegal/gray area depending on their state laws so the "friend" is likely already on their list, and all it is doing is fanning more suspicion onto them. There are few bug enforcers though (especially for door to door searches, and likely far less convictions from any enforced) thankfully and is often left to a hobbyist policed affair (much like metal detectorist in most areas).
If you really want to know though try sending a few PMs and see if they will respond, as you yourself are a fellow hobbyist obviously.