I have a can with paper straws set up for mason bees just outside the gate to one of our pastures. I kind of forgot about it for most of the summer, and when I went to check on it the other day, I was pleasantly surprised to find it almost full! There are mud capped nests from the long-horned masons and leaf-pulp capped nests from the native Georgia masons, and some tiny little enterprising individuals, whose species is unknown to me at this time, even made mud nests in the space between the straws! This does present me with a bit of a problem though, as I usually take the straws in the for the winter to protect them from birds. I can't do this without ruining the small bees' nests, so I'll have to protect them some other way, perhaps with some mesh over the can.
They do tend to multiply! We have been ordering a couple 100 straws each year and they pretty much fill them. what we haven't done is clean any out, so there are probably dead clogging some.
So far, birds have not bothered them.
I've tried just leaving the straws out over the winter unprotected, and inevitably I find them pulled out of the can and scattered on the ground. I'm assuming it's birds that are doing it, but I suppose it could be squirrels too.