Rysn realises what the creatures are. They are an Abyssal Ant Swarm. A very dangerous collection of creatures that could hold their own in a fight with even a nalfeshnee. They will have to be dealt with in one way or another, since they seem to be hanging around the Well you need currently. Of course, you could always either lead them away, or perhaps wait for them to leave. Or maybe some other way may occur to deal with them.
Spoiler: OOC Actions
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Rysn, you will be able to learn their details, which are on page 166 of the Fiend Folio. It is a 3.5 source, but close enough.