This was determined based on phylogeny (origin), biochemistry, and anatomy. Fungi are considered to be one of the developmental lines within the supergroup Opisthokonta, one of the six into which nucleobases (eukaryotes) are divided, which includes, among others, animals.
Like animals, fungi are heterotrophic and feed on organic nutrients in their environment, which they usually break down by releasing enzymes, making them soluble and available to them.
A common feature of fungi and animals is the production of the polysaccharide glycogen as a storage substance, while plants produce starch.
Although fungi, like plants, do not move, in the animal world, some individuals spend most of their lives in one place, such as sponges and hard corals.
