Even a female Ruby Throat can guard 3 feeders. If you only have 2-3 birds, then one aggressive bird might be able to keep them all away from the feeders. I try to put at least 4 feeders up when the first birds come as to make it difficult for one bird to keep the others away. Those feeders are usually in a 40 foot area. Now when the first Rubys arrive, one birds will run himself crazy chasing all the other birds; but the birds just keep coming and he gives up eventually. I only know RTs, but some variation of this should work. Might have to spread the feeders out.

If so, your best bet would be a pre-emergent. Polygonum pensylvanicum is an annual and could be prevented from sprouting. Everything (that I can think of) that is commonly called monkey grass is perennial, and so would not be affected by a properly applied pre-emergent.

"Glechoma hederacea" is known variously as Creeping Charlie, Ground Ivy, Gill over the ground, Hedgemaids, Alehoof, and &*^%?! This member of the mint family grows in many soils but does best in moist, acidic, infertile soils, so the first step in control is a good soil test and then correcting any problems found. Generally any broad leaf plant poison containing 2,4,D will suppress this although repeat applications will be necessary since birds drop seeds this plant grows from everywhere. http://msue.anr.msu.edu/resources/ground-ivy-control-for-home-lawns

"Amazon does is to tell you if you have already purchased the book" Just an FYI that Amazon only tells you if you bought a particular version of a book. If another version comes out, it doesn't tell you. I've run into that several times. If a book sounds familiar, I usually go to my content and search for it to see if I have an earlier version. In my case, I have the Kindle Voyage -- precursor to the Kindle Oasis. I bought it in 2014. It has both auto-brightness and adaptive display. Auto-brightness changes the brightness depending on the ambient light based on what you say you like for brightness. Adaptive brightness then gradually dims the brightness as your eyes adjust. I was skeptical about adaptive, but it works pretty well. Sometimes it does dim a bit too much, but not often. It also has page turn buttons that can be turned off if you don't like them -- I like them. I like that I can read in bed and not bother my DH with a light. I had the Kindle Keyboard 2, but it stopped holding a charge after a couple of years. I also have a Kindle Fire HD 7" that I use as a tablet. It works fine for me since I don't use them much. (I'm not a big fan of tablets -- I prefer an actual keyboard and larger screen). I'm not a fan of Apple products -- they minimize the amount of customization you can do and I customize EVERYTHING to the hilt. so they don't work for me. (I tried a Mac and hated the limitations.) We got my 85-year old mom a 10" Kindle Fire HD b/c she likes to read the newspaper online and the Fire works better than the e-readers for that. She also uses it as a tablet and hasn't complained about it. It's been especially helpful for her now, during COVID-19, as well as when she had a knee replaced a couple of years ago. I got the "reading gene" from her -- she's always been an avid reader! (She's into historical fiction/romance, I'm into Science Fiction and some Fantasy.)