Log homes can rot if they're not properly made or cared for.
But when log homes are built they're built using a certain pattern that prevents the logs from rotting and to allow airspace between the logs.
The logs that log homes are built with are also treated with a chemical to prevent the decay and rot of the logs.
Older log homes probably used creosote which you can still use today if you want too to prevent the rot of the logs on the log homes but you can buy a better treatment for the logs on the log homes through the internet or other stores.
My log home was treated with a chemical treatment known as PeneTreat.
The log home builder left me with some to use up and treat the home with but I'm not sure where you actually buy it although a log home builder could likely get you some if you need some.