Blue skies above, and green trees below- it's a beautiful day, and Luca and Melua are in for a BIG treat - the biggest, in fact. Can you guess what it is? Elephants. The world's largest land animal. And these gentle giants of Zambia are no exception. Despite their size, their greyish-brown skin helps them blend into the tree-trunks. But when you're that big, it's not long before your cover is blown and you get spotted.