In my experience, large masses of eggs laid in weird places are usually from some sort of moth. I've watched them lay big rafts of eggs on window screen.

Wow, how long did they stay hanging on the clothes line? I would think thats not something you'd see after just a few hours outside. I would make sure to bring in your laundry as soon as its dry.

It's interesting, highlander, but this is a very common issue....egg masses on laundry hanging out to dry. Who knows why.

We just found some as well. May 2016 Hung out the laundry after our dryer broke and forgot about them over night. My daughter found them when folding her shirt. She scraped some off and larvae came out. Totally freaked her out. I guess there are more reasons to have a dryer than stiff towels. I am thankful our dryer is fixed.

oh my gosh ive been finding these too and they are even imbedded on my laundry lines.. No idea who is laying them but its totally grossing me out as well