I moved into my new home in March of 2007 and my neighbor hasn’t mowed her backyard once. I see critters of all types coming into my lawn from hers and my dog even caught a mouse a few weeks ago. She cuts her front - once every 2 weeks - but not the back. I’m debating about reporting her anonymously to the HOA because I’m getting too many little creatures in my yard and some are running under my porch.
Don't do that. Just buy some round-up concentrate, wait for her to leave and soak the area.
I had a neighbor when I rented years ago who refused to cut up to his property line...there was a fence along half of it. I just Round-up'd 4 feet into his yard, blamed it on the landlord and he cut it thereafter :)