When, or DO, you replace the rubber hoses?

When had my airbox off there were two rubber tubes attached to some device that was screwed onto the airbox. I noticed the rubber was starting to crack and started looking at the rest of the hoses. None are really bad, but there are signs they getting old.

I squeezed the coolant hose and it didn't crack or make any noises, it seemed fine, but the some of the others are looking like they're on the way out.