Awesome! I play a very similar deck and have tweaked it a lot.
https://deckstats.net/decks/56090/399745-oh-rats/en I have a couple of main board
Duress for the cards mentioned above and more in the side board, have 3
thrumming stone vs. 4, 2
marrow-gnawer (with a
diabolic tutor to go find either.) I have 4 main board
typhoid rats to stall the board out until I can get the pack rats or
relentless rats going (you may not need to worry about that with the dark rituals, I had some in there, but removed them to make it modern-legal.) I have 4 slots for removal, but I vary them a bit for a bit more game 1 resiliency and then more in the sideboard to swap out after I see what they're playing. I have a playset of
fatal push in another standard deck now that will probably find a home here eventually. I started with a lot more
relentless rats, but finally curved it down to 18. It usually goes off in one turn with that few, but even if it misses, you can try again on your next main phase and get more out to bump the ones you will attack with on that turn.
Swarmyard is a must-have for this deck! It's saved me so many times!
Have fun with it!!