We've got a new paper out, headed by technician and gummy seed wrangler extraordinaire, Vincent Pan.
It is available here or email any of us for a PDF.
In short, we found that seeds bound to the ground with mucilage (a common property of diverse seeds) were better protected from harvester ants than unbound seeds. We also incorporated a meta-analysis of mucilage adhesion and found that there were some climatic (dryness, solar intensity) and life history variables (annuals) that predicted "stickier" seeds. We are excited about these results and hope both the small-scale protection and the larger-scale trends lead to more people studying mucilage and finding cool things!