Hi @Elisabeth1168
Tough situation. Unfortunately, you never get a second chance to make a first impression. Not sure how long this reservation is for, but the longer they stay the worst the situation becomes. I think at a minimum you will get a negative review no matter what you do. Although this was a legitmate mistake on the part of the housekeeper, it resulted in a very poor first impression. I agree that a few insects are to be expected in a rural area, but you don't expect ants to be everywhere on the counter. I have co-hosted for a property in a rural area and she not only doesn't leave any open food on counters, she has a sign to warn guests NOT to leave food open on counters and to keep in sealed packaging or in the refrigerator. Otherwise, the ants will swarm on any food left out...it's like ringing the dinner bell for them. Once the source of food is eliminated, they generally don't come back. You could consider getting them to cancel and offer a refund of the cleaning fee and at least the first night.
No matter what you do at this point, they will still most likey leave a bad review. You can mitigate it with a public, factual response. Explain what happened and that you had cleaning come back to remedy and gave them a refund. Most future guests will understand this is not the norm and was just a "blip" and not indicative of the cleanliness of your property.