How do squirrels know when bird seed is put out? They seem to be there very quickly after seed has been put?

They are very observant. they were probably watching you from a treetop, or telephone line, or housetop somewhere close.

They remember where the food has been previously.

They have a very acute sense of smell. I have watched them moving about the yard, with their nose to the ground, they suddenly stop and dig, and come up with a prize peanut.

they are intelligent little creatures and these are some of their survival skills.

Hope

P. S. they love sunflower seeds.

Well if they eat alot like birds when it comes to seeds I bet the watch what the birds are doing. My grammie told me if you want them to stop eating your bird food mix it with hot pepper powder. the birds really don't mind the heat.

Squirrels have very good hearing, eyesight, and an even better sense of smell. I hope this helps.

Eyes, ears, and a keen sense of smell.

They carry binoculars!