White Egg Layers

I have a mixed flock of about...45 hens...I think!! I know I have a couple of breeds that will lay white eggs, such as 1 White Leghorn, 1 Brown Leghorn, & 2 Seabrights. As far as I know, that is it for white layers. The rest--Australorps, Ameracaunas, RIR, BO, Buff Brahama, Silver Lace, etc are all tinted layers. Here's the issue...I have been checking the property for hidden caches of eggs because not that many are laying in the nests. Early last week, all was clear. Saturday, I noticed the White Leghorn sneaking around some tires behind the garage & went & checked. I found 20 eggs, mostly white, in a tire. So who is laying all the white eggs? There were also a couple of TINY light tan eggs. I would assume they were Seabright-sized, as they are the only Bantam hens I have. The rest were medium to large white eggs.

I do have 2 ducks (1 male for sure, the other I hope is female), 2 guineas (both annoying, sex unknown) & a bunch of mutts from a Polish Roo & Australorp, RIR, or Ameracauna hens. I know Polish lay white eggs. could their offspring lay white eggs? Only one of the cached eggs was larger, possibly duck? I can't come up with how there could be that many WHITE eggs in 4-5 days time.

Ideas??

 

I checked the hiding places on Tuesday evening...& found the cache on Saturday. So, 3-1/2 days...20 eggs (17 of which were white, 1 of which was duck??). Who knows?? Somebody has been busy!