I would and show that action was taken.

It might not be required but it's always good to disclose something like this. Follow Gabe Sanders' advice, disclose there was pest remediation and include the receipt.  

It depends on the states laws. Honesty is the best policy but each state has different laws. If you are talking about a legal point of view this is the case but from a responsible person point of view wouldn't you want to know if you were the buyer?

If they're gone and it's guaranteed that they're gone, I would forget it.

I would, especially if the are red or fire ants that could bite kids or pets playing in the yard.

Of course! Thge more you disclose, the less likely you will be sued over something!

I encourage all sellers to disclose all known material facts.   Let the buyers discern what is important or not to them, more information the better.  Would I be concerned about ants if I was the buyer?  No, but opinions vary.

I have seen inspectors comment to the effect that there had been an infestation [of whatever], they noted it with the commentary that it had been taken care of. If I were the listing agent and was aware of it, I would disclose it. The buyers should know, in case the ants reappear, or just to be on the lookout for them.

Wanda,

Disclose and show the action taken to get rid of the ants. A

Yesterday a big dark storm cloud obscured the sun from my house. Do I need to disclose 'storm cloud can obfuscate' here in the SUN SHINE state?

A termite swarm was spotted at the shed and back fence, but later no termites found. Do I disclose?

Had new sod installed. Must owner disclose if the sod was replaced because of sod worms, beetles or wild Bahia grass or personal preference? (All are part of the FLORIDA environment)

Left back door open and mosquitoes potentially carrying disease of every sort allowed into the house, still swatting them....DISCLOSE?

Big century oak in back yard next door. Excellent location for a nesting bald Eagle? (they do nest here) If that happens, activity in your back yard is greatly influenced. Disclose even the potential of such real situation?

Gator spotted in golf course pond just over the back fence? Disclose?

As you can see, the 'disclose everything' could result is a exhaustive list that would frighten every buyer away. Common sense must prevail.

Here in Florida, insects and other creepy crawly things are a certainty. The question is never 'if' but 'when?"

ONLY if structural damage was caused and infestation not current, or materially effects the value of the property, would disclosure be needed. 

We can all share war stories regarding exceptions. I know of the house that had a bee problem. Bees eradicated. No one anticipated the consequeses and was undetected by home inspector or WDO expert.

I have yet to see an appraiser add value or remove value based on the absence of a pest.

And in your example, ants are a part of the environment.  And for $17, they can be eliminated by products purchased from Home Depot.

My disclosure would be, 'Home is under a current, transferrable, 'Annual Pest Control' contract.

I would advice them to disclose and show the receipt  that they got rid of it.

There is a time frame for disclosures. So, yes, if it happened in last few months, they have to disclosure what they did.

Honesty is the best policy, in this situation.  Perhaps it would help if you provide backup from exterminator, confirming they have been eradicated and "x" is recomnmended to complete the treatment (i.e., perhaps another 1 year of spraying will completely eradicate the possibility of them coming back?) or extermination was completed and no further treatment necessary. 

in my state if you know it you disclose it.  And pest issues are covered on the seller's disclosure.  

Ants? Like in Fire Ants?  Either way, no matter what kind of ants they were I think a potential buyer would want to know this.

Wanda - If I was aware of the issue, I would ask the sellers to disclose. If I didn't know about it, I wouldn't be able to tell the sellers to include that in their disclosure.

It sounds like it was a big enough issue when you say there were millions of ants, and the fact that they were in the home. We have a Sellers Advisory form that specifically has a miscellaneous area that asks about rodents, insects, and pests. 

Carpenter ants, probably but insects rule here in Florida so other than the required WDO certification if this were the case I would be disclosing until the cows came home. 

It is always best to disclose even if they got rid of them. Otherwise a buyer could say it was concealed knowledge. 

Disclose

Wanda Kubat-Nerdin known defects should be disclosed - if disclosure is mandatory in your state.

In MA, seller's disclosure is not mandatory.

Wanda, I have to agree with all the previous responders on disclosing the prior issue.

If you have to ask...

I would disclose and show that action was taken.  I think with a small pest problem time has to be a factor.

When in doubt disclose it and have proof the problem has been remedied.

Of course!  There are only three words in real estate: Disclose, Disclose, Disclose.