"They are animals."
Translation:Ce sont des animaux.
"Ils ont" means "they have", so it's not correct here.
Maybe you wanted to say "Ils sont", but that's also wrong as well, because there is this weird rule that "ce" is always used with être when the second element is a noun, and "il/elle/ils/elles" are used when it's an adjective or an adverb:
Ce sont des animaux = They are animals ("des animaux" is a noun - ce)
Ils sont grands = They are tall ("grands" is an adjective - ils)
"Ils sont des animaux" should also be an acceptable answer because "ils/elles" is the traditional translation of "they", and in conjunction with "sont", should be the equivalent of "ce sont"
"Ils/Elles sont + adjectives" is correct to translate "they are + adjective"
But "il/elle est + determiner + noun" has to change to "c'est + determiner + noun" and "ils/elles sont + determiner + noun" has to change to "ce sont + determiner + noun".
Determiners are: articles, possessives, demonstratives, numbers, etc.