Pet Rats
Most shared houses don’t allow residents to keep pets because they’re a source of tension. They may destroy the property or create a bad smell that infuriates everybody else. One of this Redditor’s worst roommates had a horrible attitude toward cleaning but her pets didn’t help.

“The girl who kept pet rats, which she never kept in their cage,” TerraBeastie wrote. “They s*** everywhere. She was so filthy I once watched her spill wine on the floor, look at it, and walk away. I finally cleaned it up a week later.” This is vile behavior but she didn’t care at all.