Funny story - What in the world was that?

So a Texan goes touring in Australia. He wants to see some of the local agriculture.



His guide shows him a grove of grapefruit. The Texan laughs: "Why, in Texas, we"ve got lemons bigger"n that!"
His guide shows him a patch of watermelons. The Texan laughs again: "Why, in Texas, we"ve got cucumbers bigger"n that!"
His guide shows him an apple orchard. The Texan laughs a third time: "Why, in Texas, we"ve got cherries bigger"n that!"
Suddenly, a herd of kangaroos runs across the road. The Texan jumps up, startled. "What in the world was that?"
His guide answers, in a quiet, matter-of-fact voice: "Mice."