I can’t remember where I heard this first but it I’ve been thinking about it for a few days now. Kudos to whomever thought of it.
It’s the problem of termites. Lots of problems come and go. Many will take care of themselves. But when you see a termite in the framing of your house? Then you have entered into a situation where you will positively have to act. The very fact that you see this tiny creature with its trail of powdery wood left behind means that you must act.
You can act now, and your options are usually easy and inexpensive. You can act later but your options will be expensive, invasive, and possibly catastrophic.
So be on the lookout for termites.