How do ants find food, and how far can they smell?

Just to add  few details to MackThe Knife's answer:

1. The sense of smell in ants located (mainly) in their feelers.

2. anta (As many other insects) can smell even some single molecules-smell of organic and inorganic  materials. And can distinguish a special smell as far as tens meters.

3. They can notice so small amunt of smell as 1/10Xexp20 gram/smc air !!!!

4.When they find something suitable as a food - they eat a bit, and begin to emit a "pathway pheromone" spreading it along the way home.

5. in their home they deliver the news by touching their feelers with their sisters. any ant that goes in this path strengthen the smell of the path, till the foof is obserbfinished and they stop going in the path.

6. To find their way they are helped  by their capability to observe the sun-light polarity.

7.Another  important pheromone is the "grouping pheromone", they use to invite their friends to the feast.

ants can smell up to 6 miles  away. Especially keen scent for sugar. Especially kool aid.

It is one thing to smell food but quite another to determine from which direction. How do they ascertain the direction from which the scent of food emanates? As far as detecting sugar from many miles away, thats a circle approximately 12 miles in diameter. In that amount of space there must be millions of places where sugar is located. That must lead to a great amount of confusion. How can they smell sugar that's just beyond the specimen that's closest to them. It seems to me that they should be limited to only detecting the sugar that's nearest to them.

If they require an ant scent trail to lead the colony from the nest to the food, that demands that the scout knows the way back to the nest. If he has no trail to follow how does he know how to get back to the colony nest.

As for being guided by the sun, the ants in my kitchen invaded some left over food at night after all lights were off.

Too many question left unanswered.

It is one thing to smell food but quite another to determine from which direction. How do they ascertain the direction from which the scent of food emanates? As far as detecting sugar from many miles away, thats a circle approximately 12 miles in diameter. In that amount of space there must be millions of places where sugar is located. That must lead to a great amount of confusion. How can they smell sugar that's just beyond the specimen that's closest to them. It seems to me that they should be limited to only detecting the sugar that's nearest to them.

If they require an ant scent trail to lead the colony from the nest to the food, that demands that the scout knows the way back to the nest. If he has no trail to follow how does he know how to get back to the colony nest.

As for being guided by the sun, the ants in my kitchen invaded some left over food at night after all lights were off.

Too many question left unanswered.

It is one thing to smell food but quite another to determine from which direction. How do they ascertain the direction from which the scent of food emanates? As far as detecting sugar from many miles away, thats a circle approximately 12 miles in diameter. In that amount of space there must be millions of places where sugar is located. That must lead to a great amount of confusion. How can they smell sugar that's just beyond the specimen that's closest to them. It seems to me that they should be limited to only detecting the sugar that's nearest to them.

If they require an ant scent trail to lead the colony from the nest to the food, that demands that the scout knows the way back to the nest. If he has no trail to follow how does he know how to get back to the colony nest.

As for being guided by the sun, the ants in my kitchen invaded some left over food at night after all lights were off.

Too many question left unanswered.

It is one thing to smell food but quite another to determine from which direction. How do they ascertain the direction from which the scent of food emanates? As far as detecting sugar from many miles away, thats a circle approximately 12 miles in diameter. In that amount of space there must be millions of places where sugar is located. That must lead to a great amount of confusion. How can they smell sugar that's just beyond the specimen that's closest to them. It seems to me that they should be limited to only detecting the sugar that's nearest to them.

If they require an ant scent trail to lead the colony from the nest to the food, that demands that the scout knows the way back to the nest. If he has no trail to follow how does he know how to get back to the colony nest.

As for being guided by the sun, the ants in my kitchen invaded some left over food at night after all lights were off.

Too many question left unanswered.

It is one thing to smell food but quite another to determine from which direction. How do they ascertain the direction from which the scent of food emanates? As far as detecting sugar from many miles away, thats a circle approximately 12 miles in diameter. In that amount of space there must be millions of places where sugar is located. That must lead to a great amount of confusion. How can they smell sugar that's just beyond the specimen that's closest to them. It seems to me that they should be limited to only detecting the sugar that's nearest to them.

If they require an ant scent trail to lead the colony from the nest to the food, that demands that the scout knows the way back to the nest. If he has no trail to follow how does he know how to get back to the colony nest.

As for being guided by the sun, the ants in my kitchen invaded some left over food at night after all lights were off.

Too many question left unanswered.

Hi,

They can smell food from around a distance of 1.2 cm.

Hope this helps. :)