When you receive your AntHome it will be in the correct position to use as it is. On the port you will see a little engraved circle... If you take a close look in this circle with be an arrow pointing towards the test tube you will attatch your ants to.
When you want to expand with a nest, in the engraved circle, using the Allen key provided, turn it to the double sided arrow. Allowing the flow of ants both ways.