"Hunting Porygon"

#PokemonGO: Hi fellow travellers, could somebody tell me in which biome does Porygon spawn? Is there any pattern in his behaviour? I could almost complete my Dex playing in my upper-medium size city, even Lapras and Snorlax (hatched), however I have never seen a Porygon, it just passed once on the Sightings for a few seconds, months ago. Any info would be very appreciated, thanks!EDIT: Thanks for all the replies. According to your reports it seems that it spawns in electric biomes and/or next to shopping malls; this coincides with the reports in my city's facebook group. It seems I have to keep on hitting my favourite hunting spot despite having no luck so far. UPDATE: Several people report that where they caught their Porygon there was no sign of electric biome, could you tell which Pokémon was spawning instead of electric?EDIT2: Minor text fixes. via /r/TheSilphRoad http://ift.tt/2hzxdRp