1/4" holes are not going to do anything. Even 4" holes won't do much, almost certainly not enough, not even with a whole lot of them.
It is really simple to add ventilation. Pick a spot, preferably high on the usually-downwind wall and furthest from the roost, and cut a big hole in the siding. Try not to sever any of your wall studs
If you have never done this before, it is quite simple, the simplest way for non-DIY type people is to drill large holes in each of teh 4 corners of where you want the opening to be, then use a power jigsaw or a (manual) keyhole saw to "connect the dots" and actually remove that rectangle of siding.
Then secure hardwarecloth over it, maybe make a hinged flap to close it down partly or wholly according to circumstances, and there ya go, it's a vent. Total cost, one scrap of hardwarecloth and maybe a pair of small hinges if you get all fancy
I would recommend making vents LARGE and MULTIPLE. It is way better to have more ventilation available than you need to have open at the moment (you can always close some of it!) than to discover, as you have now, that you ain't got enough and have to get out the Sawzall in the middle of winter.
Alternatively you could TRY leaving your windows partly open overnight, but whether this will do much good and whether it will cause problematic drafts depends entirely on the overall design of the coop and location of windows and roost. Really, it is easy enough to add properly-located vents that I'd suggest *that*.
Good luck, have fun,
Pat
