Translation guide
The mound or nest built by ants. In Japanese, the most common and natural term is 蟻塚 (ありづか), which specifically refers to the mound of earth. Other terms exist for the nest itself or the colony, but 蟻塚 is the best default for 'anthill'.
Referring to the visible pile of soil or sand that forms an ant nest.
The standard word for an anthill, specifically the mound of earth. Used in everyday language.
An anthill formed in the garden.
The children are observing the anthill.
Literally 'ant nest'. Can refer to the entire nest structure, including underground parts, not just the mound. Slightly broader than 蟻塚.
Dig up an anthill.
Referring to the dwelling place of ants, not necessarily a visible mound.
The most common term for an ant nest, whether it has a mound or not.
There was an ant nest under the rock.
A more technical or literary term for ant nest. Rarely used in everyday conversation.
Study an ant nest.
Referring to the community of ants, not the physical structure.
Use 蟻塚 when you specifically mean the mound of earth. Use 蟻の巣 when referring to the nest in general, especially if it's not a visible mound (e.g., inside a tree or underground).
A swarm of ants is swarming over the food.