What are the moving glowing balls in slither.io?

In slither.io, there are these little moving balls that glow. If you eat them, you grow more than just eating a regular food pellet. One thing about them that's kinda weird, is that if you move toward them they will dodge you.

For reference, here are some screenshots of them.

The purple on here:

and the violet one here:

What are these things? Are the controlled by other players? Do they have a name? What are some strategies for them?

Solution 1:

They give more mass than other bits of food, which is why they are harder to catch.

Fun fact: Dashing causes the glowing food to magnetize to you if you get close enough.

Solution 2:

The stationary balls are called 'Food' and are worth between 1 and 20 length.

The mobile balls are called 'prey' and are worth between 50 and 100 length (but you usually have to spend some length boosting to catch them).

Solution 3:

It's just energy. Don't know what it is called. It helps you get bigger and larger. When you boost in the game or are killed you lose them. They are parts of snakes