Rehab Advice- Hole in Kitchen for W/D hookups

[Jesse S.]

Hi all- full disclosure: this isn't about one of my investment properties, it's about where I am currently renting!

After moving in I noticed this gaping hole underneath the sink in my kitchen (see picture). Reason for the hole is to run the water line from the kitchen to the closet where the W/D hook-ups are. However, they clearly didn't seal up the hole in the kitchen when they were done. While we don't have any rodent/pest issues, this seems like a massive invitation for something to enter my apartment while crawling through the walls of my building. 

Any ideas on how to close the hole? I know I'm not responsible for it, but I'm a bit puzzled by the solution as the hole is large and there needs to be space for two pipes to fit through.  Help! 

[Kevin M Finley]

I'd stuff a small piece of bat insulation and then seal with scrap plywood. Surround the water line coming out with steel wool- mice hate steel wool. 

Should be able to do it for a couple bucks or just scrounge a flip after hours and grab stuff. I wouldn't even bother calling the landlord.