The Deductive Mr Horsefly. Audio story narrated in British English.

Mr. Horsefly was the new head of the prairie post office. He had put a lot of time and effort into getting this highly respected position; he had even moved fields. If you asked Mr. Horsefly, he would tell you that he got the job thanks to his great deductive gifts.

On his first day at work, he opened up shop, and into the post office came Mr. Beetle, Mrs Spider, Miss Mantis, and Mr. Grasshopper.
Mr. Horsefly wouldn't let them so much as open their mouths.

"Don't tell me, don't tell me. I bet I can work out what each of you came for," he said, putting a book, a plastic mat, a nail file, and some protective goggles on the counter.

"The nail file will be for Mrs. Spider, without a doubt. With all the scratching she does, she'll need to put her nails right. “The mat”, he went on, without giving anyone time to react, "without even having to think about it, I give it to Mr. Grasshopper, since he must have to train pretty hard to keep all his hopping about up to a decent standard. The safety goggles have to be for Mr. Beetle, because having to spend all day with his face so close to the ground, he'll be needing something to protect his eyes. And finally, this big book here, has to be a Bible. I'll have to give that to Miss Praying Mantis, whom I would like to ask to include me in her supplications to The Almighty. As you will see..."

They didn't let him finish. The comment about the mantis - well known on the prairie for having changed her name from Miss Praying Mantis to simply Miss Mantis - was just too much for everyone, and they burst out laughing...

"Not much of a detective, are you!" said Mr. Grasshopper, between chuckles. "For a start, Mrs. Spider came for the book. She's very quiet, and doesn't scratch a soul. The mat is for Mr. Beetle, who likes to sunbathe in his swimming pool, and do it lying on his back. Miss Mantis will, of course, want the nail file. She's a bit of a flirt, you know. And the protective goggles are for me. I'm not as young as I was, and don't see to well. These days when I'm hopping on the grass I get the odd black eye..."

“Uhu”, Mr. Horsefly interrupted, recovering a little from his embarrassment, "then you do, in fact, hop on grass!"

"Yes, I do," answered the grasshopper, "but as you'll see, making your deductions based simply on prejudice, leads to more misses than hits..."

How right he was! Just a few days later, after having met all the insects in person, Mr. Horsefly had a good laugh while telling this story about his deductions made from prejudice without yet having met a soul. And he understood that judging without knowing is a practice for fools.