PLEASE HELP GERBIL INVASION THIS IS NOT A JOKE ok so a month ago I rented an apartment to an old lad

Some hamsters will come back to the cage on their own. Leave the cage open on the floor (with a supply of fresh food), near its usual location (or closer to where the hamster is hiding if you suspect a distant hiding spot). You may have to stay up late to close the door on your hamster when he or she returns, though often they are happy to be home and settle in for a nap after eating.

Set up a "bucket trap" by getting a bucket (deep enough that a hamster couldn't get out of but not so deep that a hamster would get hurt falling in), and place a thick towel on the bottom. On top of the towel you place some really tasty treats such as a thin layer of peanut butter on a cracker, apple slices, and/or cheese (something the hamster will easily smell). Then, make some sort of ramp up the outside of the bucket using wood, a wire shelf, or books stacked to make a staircase. The idea is that the hamster will go up the ramp in search of the food and jump into the bucket to get it, but can't climb back out. I have never tried this personally but have heard it works; the trick is to make the treat so irresistible the hamster will be willing to jump in the bucket for it.

As a last resort, get a humane mouse trap, also called a live mouse trap (the kind that is a box that traps the mouse without killing it) and bait it with peanut butter. These do occasionally malfunction so could possibly injure your hamster, but that is fairly unlikely and they usually work well.