You want to get rid of that rat.
Use the bottom right drawer to get a rusty old MOUSETRAP. On the counter is an APPLE. Take it. At the bottom is an dead PLANT with thorns. Pick that up too. Walk to the left to see the root of all evil: the mouse hole. Walk to the north into the bathroom.
On the floor is an old BRUSH. Might be usefull. On the lower left edge of the bathtub is a bar of SOAP. And in the right side drawer under the sink you find STEEL WOOL. Now that you have the ingredients it’s time to make a nice trap.
Use the steel wool on the tap to make it wet and then use it on the mousetrap to clean it. The thorns on the dead plant are somewhat loose and when you use it on yourself, the THORNS come off. Use the soap with the tap to make it sticky, then use the soap with the brush to make the head sticky. Use the thorns with the sticky brush to make the brush sharp. Use the sharp brush with the apple to make it more of a bite size apple. Use the smaller apple with the mousetrap to serve as bait.
Walk to the south and use the mousetrap on the mouse hole. Now all you have to do is wait…
Game source: A copy of the game was found here on the internet.