Click on the "bag" icon (your items) and chhose the card with the mouse. If you release it near the owl, it will be eaten (chomp). Thereafter the owl will follow you in the underground passages (but not in the castle).
It is a mechanical mouse. (see related question)
You do not get or use a bucket on Astro Knights Island.
There is no treasure chest on Astro Knights Island.
At Mordred's secret lab, when the owl flies out, you feed the mouse to the mechanical owl. The owl becomes your friend and follows you.
Feed it the mechanical mouse (from the Maid's room) and the owl will follow you.
Click on his card in your items bag.
There are no bird eggs in astro knights island.
its on the island
To catch the mechanical mouse, in the Princess's Maid's room (castle first floor left).
How do you talk to the girl in the hay loft at astro knights island?
After the Astro Knights island release in June 2009, the next regular feature was Poptropica's Haunted House in October 2009. (Available through the Poptropica Store) The next scheduled island was Counterfeit Island.
There is no Mechanical Island. However, Astro Knights Island is replete with robot plants and animals, while Steamworks island has actual plant monsters as well as mechanical devices. Game Show Island is populated by robots. (see the related questions)