Male cats run away as adults because they are in estrus. When male cats are in estrus as adults, they will want to go out to find female cats for mating. If the male cat hears a female cat whining downstairs, he will Will always want to go out to find a female cat, so will sneak out when the owner is not paying attention.
If the male cat wants to go out or urinate indiscriminately, it is best to take the male cat for sterilization operation, which can slow down or prevent this from happening. Close the doors and windows of your home to avoid tragedies as much as possible.
