In One Sentence: Student Body by F. L. Wallace

A story about humans colonizing a new world and finding them outsmarted by the local biodiversity.

In two days, the machine was ready.

It was delivered in a small crate to the warehouse. The crate was opened and the machine leaped out and stood there, poised.

“A cat!” exclaimed the quartermaster, pleased. He stretched out his hand toward the black fuzzy robot.

Even about himself there were many things man didn’t know, dark patches in his knowledge which theory simply had to pass over. About other creatures, his ignorance was sometimes limitless.