I live in southeastern Pennsylvania and have for forty years. For the first time this year, I have very tiny ants that collect bits of dried leaves, insect parts, etc and pile them up in little piles. on a brick porch. I think the piles are at the opening that leads to the nest. What are they?
Sue, PA, USA
This is a very interesting question and without seeing the piles myself I have two guesses: Either the ants pile up dirt that comes up when they build a tunnel system in the ground or the piles are waste dumps. If the piles are located on the entrance to the nest, this might indicate that the ants have built a large subterranean tunnel system. The dirt that is being removed to form the tunnels is then piled up at the nest entrance (see picture below for an example).
Since you mentioned that the ants also deposit dried leaves and insect parts on the piles, they might be waste dumps. Since ants live in colonies with large numbers, diseases can spread easily and ants have developed hygienic behaviors to deal with this. Please read this post to find out more on hygienic behavior in ants.
Thanks for contacting us,
Steffi Kautz & the AntAsk Team