The expression, “Wherever the body is, there the eagles will be gathered together” is found in Luke 17:37.

Luk 17:37  And they answered and said to Him, “Where, Lord?” So He said to them, “Wherever the body [soma] is, there the eagles will be gathered together.”

A very similar expression is also found in Matthew 24:28.

Mat 24:28  For wherever the carcass [ptoma] is, there the eagles will be gathered together.

The difference is, in Luke 17:37, the word “body” is used (Greek soma), which can mean a living or a dead body, whereas in Mat 24:28, the word “carcass” is used (Greek ptoma), which means specifically a dead body.

Sometimes people want to read all sorts of things into these enigmatic verses, which is completely unwarranted because their meaning is quite clear based on their context. 

“Wherever the body (or carcass) is, there the eagles will be gathered together” is a figure of speech.  Eagles, although predators, are opportunistic scavengers.  If they see a carcass, they will fly down to it for a free meal.  In other words, the gathering of eagles shows there is a carcass nearby.  “Wherever the body is, there the eagles will be gathered together” is a figure of speech meaning, it will be obvious if you look for the signs. 

With this in mind let’s look at the context of Mat 24:28.

Mat 24:23  “Then if anyone says to you, ‘Look, here is the Christ!’ or ‘There!’ do not believe it.
Mat 24:24  For false christs and false prophets will rise and show great signs and wonders to deceive, if possible, even the elect.
Mat 24:25  See, I have told you beforehand.

The context is the second coming of Jesus Christ and how to avoid being deceived by false christs.

Mat 24:26  “Therefore if they say to you, ‘Look, He is in the desert!’ do not go out; or ‘Look, He is in the inner rooms!’ do not believe it.
Mat 24:27  For as the lightning comes from the east and flashes to the west, so also will the coming of the Son of Man be.

Jesus Christ is not going to come secretly.  We will not need someone to tell us where he is.  Just as everyone sees lightning when it flashes, so everyone will see Jesus Christ returning.

Mat 24:28  For wherever the carcass is, there the eagles will be gathered together.

What does this verse mean?  In the same way that it is obvious there is a carcass nearby if you see eagles gathered together, so it will be obvious when Jesus Christ returns.

For a discussion on Luke 17:37, see ‘What does “two men will be in the field, one will be taken and the other left” mean?‘