These are some photos of a Pseudomyrmex species on the plant Vachellia collinsii that I took in Yucatan.

This pair is a famous example of symbiosis. The plant has hollow thorns in which the ants live, and the ants provide protection. The plant also produces those yellow blobs called ‘beltian bodies’ to feed these ants.

Another related fun fact: The ‘vegetarian’ jumping spider Bagheera kiplingi also feeds on these beltian bodies.