If [most] life begins at the microscopic scale, wouldn't there be a higher chance of intelligence developing at much smaller sizes than the average human body?

Have we even learned if there's a minimum body size required for sapient intelligence to develop?

We can already see different types of intelligence in comparatively-small creatures like octopuses, but even overlooked organisms as tiny as the ant show forms of intelligence! Social communication, tool usage, agriculture, even domestication of other species (e.g. aphids.)