Wooden Sign arrow things?

[Fritzgerald]

Suddenly appeared outside one of my walls, looks like it has a ladder and building materials around it, plus these two wooden arrows sign pointy things. What is it and what does it do?

[Ordinary Time]

Catapult. manned by one or two hammer guys. will take up their time.

[Fritzgerald]

Originally posted by Ordinary Time:

Catapult. manned by one or two hammer guys. will take up their time.

Should I just ignore it if there isn't any wall spots around?

[The_Pastmaster]

Catapults have an Area of Effect sort of and can kill a lot of minions in one pull.

[Max Colby]

They're definetely needed. Usually once mine are killed, that side gets destroyed the next couple go arounds.

If you can build catapults, you should have some walls.

[Time Lord Iroh]

Originally posted by Fritzgerald:

Originally posted by Ordinary Time:

Catapult. manned by one or two hammer guys. will take up their time.

Should I just ignore it if there isn't any wall spots around?

Don't ignore it. The arrows mean the workers/builders will take it to the farthest wall on that side. Catapults are really useful and you definitly need them for the later nights.

[Diarmuhnd]

this guide is from the New Lands Kingdoms, but much of the information is accurate for Classic.
http://steamcommunity.com/sharedfiles/filedetails/?id=740733723 catapults are the only buildings that move. Section III-II (Buildings part 2) the last one.