Question

How do spambots, or any type of bot, work?

Answer 1

they execute some code

Answer 2

In the web, a bot analyses a site to find a matching expression - for example a regex for an email address - and then stores these somewhere for later use. Often they move forward through links on the site to expand their area.
There are too many kinds of bots to explain every single one. For detailed information please explain in what area you're interested.

Answer 3

lol Tomas. You're right! they do execute some code. Amazingly insightful as always. ;)