Ants and earthworms are widely recognized as important soil ecosystem engineers that contribute to various ecosystem processes such as nutrient cycling, production of organic matter, and soil formation, and are thus important for maintaining healthy soils within agroecosystems. Addressing the dominant ant and earthworm taxa on Puerto Rican coffee farms, I propose the existence of a “soil mosaic” of contrasting soil functional domains, driven by the ant Solenopsis invicta exerting top-down control on populations of the earthworm Pontoscolex corethrurus, which then finds refuge elsewhere, forming discrete areas of contrasting influence on soils by each organism. These contrasting effects then create a mosaic of soil patches of differing quality, which will ultimately affect crop production within the coffee agroecosystem. Through this work I aim to broaden the current understanding of the ecological relationship between ants and earthworms and their shared functional impact on the generation and maintenance of soil structure, fertility, and plant growth within the coffee agroecosystem.