This one is not exclusively for cycling, but since I caught it from a race commentary yesterday, it’s legit. To ‘have ants in your hands’ is to have pins and needles and maybe numbness. This is an all-too-common problem usually caused by an incorrect position on the bike.
Incidentally, what I heard Cyrille Guimard saying yesterday was that a rider in the breakaway ‘…a des fourmis dans les jambes‘ (legs). I’m not sure how he knew that, but he’s been in cycling for about 2 centuries, so I suppose he knows it when he sees it.
Later that day…
Thanks to Rich we now know that what Cyrille Guimard was saying on TV yesterday made perfect cycling sense: avoir des fourmis dans les jambes means that the rider in question was “itching to attack”.
In the end this actually was cycling jargon. I just got my appendages wrong.
The Vicious Cycle 
Well, fourmis dans les jambes isn’t really the same – it means his itching to attack.
Oh…that’s good to know. And makes sense!
As long as we all recognize that “incorrect position on the bike” is always relative. Let’s face it, even CORRECT position on the bike is a bit of an absurdity from any remotely commonsensical or honest point of view. It’s like me talking about comfortable ski boots. Really what it means is, “This position allows me to execute my sport to the best of my ability, motivated as I am by a slew of highly irrational factors. But no sane person would do anything like this and tolerate it for more than a few minutes.”