I've noticed fire ants crawling on my okra plants, particularly where new okra are starting to grow. However, the okra does not seem to be harmed. Is this something I should be concerned about?
As I said in my answer to another question, there's likely more of a risk to a human being bit, especially someone who disturbs the nest, than any risk to the plant. Fire ants are omnivorous and eat plants as well as other insects (which could be either a positive or a negative, depending on if they're attacking insects that are beneficial or damaging to your plants), but they're probably always going to be less of a risk to your plant than other insect/fungal/viral threats, and it's definitely going to be more of a risk to the gardener than the garden.
Here's more on fire ants. (warning: PDF)