No, the ants are not fitted with receivers, the transmitter/receiver that is built into the helmet and earpiece talks directly to the ants' antennas. Hanks gives the "sciencey" explanation in the film:
Hank Pym: I use electromagnetic waves to stimulate their olfactory nerve center. I speak to them. I can go anywhere, hear anything, and see everything.
Then in Marvel's Ant-Man: The Art of the Movie we get a little bit more detail of how it works.
The ants are controlled via a small earpiece in the Ant-Man helmet. To help Scott learn to communicate with the ants, Hank gives him the earpiece to practice. The device functions much like the ant's antennas: It conveys information from the user, sharing thoughts and demands with the ants. The ants will only comply when the user is clear and focused--not Scott's strong points.
Marvel's Ant-Man: The Art of the Movie
The devices we see fitted to the ants are actually things to help utilise them better. For example we see the following:
We also see the winch ant that lowers Scott in to grab the Yellowjacket suit and a few others. In Marvel's Ant-Man: The Art of the Movie we also have a bunch of concept art for even crazier ideas the ants could have had attached for them but were abandoned.