noun
mud bath; mud pit
Refers to a muddy area where animals, especially pigs or wild boar, wallow to cool off or protect their skin.
イノシシがぬた場で泥浴びをしている。
A wild boar is taking a mud bath in the wallow.
山の中に自然のぬた場を見つけた。
We found a natural mud pit in the mountains.
泥浴び is the act of bathing in mud, while ぬた場 is the place where it happens.
The word ぬた (nuta) is an old term for a muddy or swampy place, and 場 (ba) means 'place'. The exact origin of ぬた is uncertain, but it may be related to the verb ぬたる (to be muddy).