Back in earlier editions of D&D, elves had chance of spotting secret and concealed doors just by passing within 10 feet of them. This was usually a 1 in 6 chance. In later editions they would also get bonuses to “Search” checks.”

I’ve always chalked this up to elves somehow having superior senses.

But lately I got into a discussion about Elven Infravision. And somebody said, “Maybe that’s how elves can spot hidden doors better than other races.”

They can see the air temperature differences around the door.

I never really under stood why elves, in earlier editions, could see in the infrared spectrum. But I guess that’s good enough explanation as to why elves can find secret door easier than other other races as any.