Hi EricBC, I have the similar problem as you described.
I have much bigger number of worms and even maybe 2 or more different species (i call the creatures as worms) but the bigges of them live in the same places as you have.
First I realised that i have worms in 2013. I use medications (mostly antyhelmintics) to keep worms paralized (as some of them tend to move and crawl and vibrate and do other kind of movements inside my body).
Could you please reply on my google email (you can google it using 'md2017ok') - i would like to discuss with you this problem and to share experience. (unfortunately this website could not verify my email and gave mistakes while verification).