From Horace Zeng:

Another remarkable example of tool use in ants: fire ants “paving” sticky surfaces. I’ve seen signs of this behavior, but I didn’t expect it to be so robust until my friend told me about it (see more in Wen et al., 2021 Insect Science). You can try it yourself by putting a piece of paper with tape on a healthy fire ant mount (disturb them a little to make the process faster).

[Horace Zeng | Via BIS]