Why are certain places Pokemon nests and not others?
Just curious if anyone has any information on why certain places, usually parks, are pokemon nests while others aren't. I think part of me just wishes my nearby park with 4 stops and a gym would have qualified to be in the nest rotation. Does it have something to do with Ingress? Cell phone traffic combined with whether or not it's a public recreational spot seems to be the best candidate. However that doesn't seem to explain why some similar areas are nests and others are not. I highly doubt these spots were manually chosen. I'm just highly curious as to if anyone knows or has any theories. Edit: I use Silph Road Atlas to find nests.
Answers
Some stay and just change species, others disappear and new ones crop up. I lost one in a field near my house a few migrations ago (before the Halloween event), but the last migration saw a new nest occur where I've never seen one before - only Magmar, but I'm keeping fingers crossed for the next migrations :-)