Intentional actions by usually solitary octopuses improve a sandy site, allowing group living in 'Octlantis'. But the buzz around the site grew quickly, creating some interesting interpretations.
Maëlle, 7, wants to know why some shells are smooth, while others are corrugated. It turns out that while corrugated shells are strong, smooth shells can move fast.
A fully protected marine reserve off a Scottish island is paying dividends.