Do Drones Alert & Report Your Position To Their Sectopod?

There's been several times when I have seen Drones come into view and they have retreated out of sight again. Then a turn or two later I get shelled by the Sectopod. I'm fairly sure I've not seen the actual Sectopod & it's not seen any of my squad.

Has anyone else had this happen?

I have observed this also. The Sectopod will sometimes just shell the area where you were spotted by some other alien. It even happened to me that I had already moved my guys away and the barrage hit the region my squad had been standing in the last turn.

But I have the feeling that the Sectopods are a bit bugged (or maybe used to be up until the last update), with their positioning and visibility and also with being able to target them (sometimes they seem to hover between layers when they are standing on a roof for example), so whether it is a bug or a feature I can't tell!

I have the impression that Sectopods can't be taken out by an overwatch trap easily exactly because they can hit you without being in your visibility range.

Aliens come in squads, much like your own squad. Just like you can start with up to 4 soldiers on a single mission, each alien squad can come with up to 4 aliens in it. When a Drone sees you, that entire squad sees you. If that Drone was in a squad with a Sectopod, the Sectopod is alerted and can then fire its mortar basically anywhere on the map. These mechanics are the same for all alien squads - you might see only one Muton and send it fleeing into the black, only for three to come out on their turn.

Luckily, the aliens have the same visibility limitations as you. The Sectopod might fire its mortar, but it is shooting at where its squad - specifically, that Drone - last saw you. All you have to do is move away from that area and you'll avoid the blasts.

Aliens cannot alert other squads unless you've mind controlled one and it has moved into the vision range of a new squad.

Sectopod does not need line of sight on location it's going to shell. As such, it will occasionally use other aliens as "spotters", much like you would use your soldiers for Squad Sight snipers.