A tenant called their manager to complain about a horrible smell every time the furnace turned on, that was just getting worse over the winter. (this is the first their manager had heard about it)
Their management sent over the maintenance guy right away and the stench was awful. Upon further investigation, the young son of the tenant had been using the HVAC vents to pee in, all over the house!
Maintenance got it cleaned up, The tenants were billed for the repairs, and the little boy learned where he is allowed to “go”.