The Strategic Use of Poison

Jossef stared at the back of the man in front of him as his platoon marched down the path between the nesting trees on planet X07T9. He knew what he'd see if he let his eyes stray: Little three-legged furry shapes draped limply over tree branches or hanging half in, half out of their nests on the thicker boughs. A few still held on to some of the coffee beans that had killed them.
The strategic use of poison is expressly encouraged, the orders from Earth had read.
The Critters never hurt people, but they were superb saboteurs. No matter how well-protected, the Critters found a way to get into every building or storage unit. They stole what they could carry, and destroyed everything else.

Soldiers ordered to put a stop to the constant raids found themselves unable to hurt a hair on the Critter's furry bodies. The creatures seemed to possess some kind of mind-control skills, making it impossible to shoot at them, or even grab them and push them away from their chosen targets. Plus, those things were so disgustingly cute.
So Command had come up with a different strategy. A security storage unit had been set up, filled to the roof with coffee beans. Caffeine was poison to the Critters, and for some reason they couldn't resist the fragrance of freshly roasted coffee beans.
It had taken the three-legged creatures several days to figure out how to break into that storage, but figure it out they had. And now they were all dead, and Jossef's unit was here to take over the territory and clean it up for the first wave of settlers.
There was a bend in the path, and Jossef's eyes fell on the tree in front of him. A family of two adult Critters and six younglings hung over the branches, a handful of poisonous beans clutched in the forehand of the smallest one. The family looked pathetic, unbearably cute even in death.
Jossef gagged. This wasn't what he'd signed up for. The recruiting officers had talked about "alien monsters" and the need to protect humanity from extra-terrestrial threats. Poisoning whole villages of unarmed little creatures wasn't part of the job description.
But some rich parasites at home had decided they wanted to settle on this idyllic spot. The Critters had refused to be moved from their nesting trees, so the tribe had been wiped out to the last three-legged bundle of fur.
Or had it? Jossef's head whipped around. Had he seen a furry shape move on the edge of his vision? No. There was nothing there.
But the hair on the back of his neck rose, and a shiver ran down his back. Suddenly, the silence surrounding the company seemed ominous. Jossef risked his sergeant's wrath by breaking stride to take a closer look at his surroundings--or he tried to. Despite his intent to stop, his feet marched on.
For a moment, panic punched his chest with hammering heartbeats, and he struggled to stop, to run, to do anything but walk straight on. Then calm control reasserted itself. Had there been a reason to panic? There couldn't have been. The critters were all dead, and there was nothing threatening out there. No indeed, there wasn't. There couldn't be.
Another movement made Jossef glance to the left again.
There they were.
A group of at least fifty Critters, much larger than the average specimen, paced the company at a distance of about sixty feet. Another glance confirmed a second group did the same to the right.
His heart did another thumping dance in his chest, but this time the panic didn't make it through to his lethargic brain. The Critters moved in, herding the unresisting troops off into the forest. Jossef found his feet moving to the left, following a largish Critter as it cantered off with its uneven, three-legged gait.
Once more, he tried to stop, to turn around and run. Sweat broke out all over his body and his heart raced at a dizzying pace. But fight as he might, his unresponsive body walked forward at a steady pace. To either side, his comrades' faces were masks of fear and despair as they, too, trudged on against their will.
The march ended in a clearing, where someone had set up a long table with a row of chairs on each side. Jossef and his fellow-captives sat down, stared at the cups in front of them. Cups filled to the rim with aromatic cappuccino. The tangy scent made Jossef's mouth water, even though he somehow knew beyond the shadow of a doubt that the coffee was poisoned. He shivered as he watched his hand reach for the deadly drink.
He looked up, took in the faces of the closest Critters. Bodies held straight and tall, a ferocious look in their eyes, they weren't at all cute anymore. Watching those implacable furry warriors, Jossef doubted there'd be a human settlement on X07T9 anytime soon.
Helpless to do anything but raise the cup to his lips, Jossef drank his coffee.