AN: A Johnlock Gift Exchange fic for banditbrineshrimp, based on the prompt ""It's for an experiment, John..."

In their early days of cohabitation there is always a moment of unpredictability when John comes home and it has of course to do with his flatmate, the world's only Consulting Detective. So John isn't really surprised by the view, although it is rather unusual finding Sherlock crawling over the living room floor.

"Close the door, John, or they will get out." And it obviously doesn't stop Sherlock ordering him around.

"Who will get out?" There is no one to be seen which leaves too many frightening options.

"The grasshoppers."

"The grasshoppers?"

"Yes, you heard me, the grasshoppers."

"Why on earth do we have grasshoppers in the flat?"

"It's for an experiment."

John couldn't suppress the groan.

"What kind of experiment involves grasshoppers?"

"There was murder case in Russia where they found a blood stained grasshopper, which lead to the findings of a murder victim. I wanted to know how much drops of blood change the movement of a grasshopper."

John stares at the other man, speechless for a moment. How on earth could someone try to experiment with blood and grasshoppers?

"You're mad."

It is astonishing how indignant Sherlock still can look, even when he is on all four with completely dishevelled hair.

"This is perfectly sensible experiment. Do you have any idea …"

"And why are you on the floor?" John interrupts before Sherlock can start a whole tirade how incredibly idiotic John is.

"Because I may have left the box open."

Another, more heartfelt groan.

"Oh god. Do you know at least how many grasshoppers you had in the box?"

"45. The pet shop couldn't give me more because they needed them for their reptiles and their next delivery is not until Friday."

Sherlock actually sounded a bit petulant about that.

"So we are now looking for 45 grasshoppers?"

"Only 39, I've already located six", mumbles the Detective, already returning his attention to the floor.

John makes a step forward, a crisp noise that directs Sherlock's gaze back to him.

"Now only 38, but please John, be more careful."

With a sigh and a curse John slowly gets on his knees. "38?"

"Yes, 38, John."

The next three hours turn into something that hopefully will be funny in ten years or so. Sherlock and he scramble through the flat on their knees, suddenly jump up when they hear a chirping noise and dashing to the source. The doctor really hopes that Sherlock's weekly search for any bugs or cameras in the flat is as thorough as he pretends to be. He really doesn't need to have a video of this ridiculous enterprise and even less Mycroft seeing it.

However, they have only found 37 of the escaped grasshoppers, but they haven't heard any noise in the last twenty minutes and John is ready to assume the last one escaped when he opened the flat door. Now he only needs to convince Sherlock of this theory or he will never get any sleep tonight.

"It is possible", Sherlock says all of sudden. John turns to him and can't suppress a smile at the state the detective is in. He is pretty sure he has never seen him so battered and exhausted, even after one of his fits with several sleepless days.

"What is possible?"

"That he escaped through the door. The one you smashed was also near the door, it's only probable that another one went this way."

"So we can stop this ridiculous search?"

"Yes."

"And you will never experiment with living insects again?"

"John!" Judging from the indignant tone Sherlock hasn't come to the same conclusion. "Why on earth should I stop?"

"Because we, two grown-up men, spent the last three hours on our knees to search for fucking grasshoppers."

The blank look on the detective's face shows clearly that this is not a decisive factor. Suddenly John is very tired. He has no energy left to argue with Sherlock about that matter.

"Okay, just get them out of the flat, will you. I go to bed, you should do the same."

Without looking back he goes up to his room and more or less collapses on his bed.

The next morning there is no sign of Sherlock or the grasshoppers for that matter and John enjoys the undisturbed reading of the newspaper. He takes his time with his shower and is only a little bit shocked to find a grasshopper on the mirror looking at him. The doctor carefully takes the toothbrush mug and pulls it over the insect. He takes the mug to the kitchen and releases the little animal. It seems only fitting to set it free, after all it escaped Sherlock's experiment and the chase afterwards.