Fire Ants

[Mdrogun]

If they're that close to the nest they are almost certainly infertile. You shouldn't even be able to see the fire ant mound when you catch them. Do you have any pictures of these queens?

[Floam90s13]

If you found a "queen" next to the nest with the others there is a chance it's a male from the same colony if it was a smaller head. A simple google images search of the species may be able to confirm this. Something like "fire ant male" for example. But hey, I'm no expert. Good luck. And as the others said, that close to the colony and chances are they are fetilized yet.