Does the following excerpt say that most animals are active during the daytime?

Question

"This can take many forms. Marine life, for example, is influenced by tidal patterns. Animals tend to be active or inactive depending on the position of the sun or moon. Numerous creatures, humans included, are largely diurnal – that is, they like to come out during the hours of sunlight. Nocturnal animals, such as bats and possums,prefer to forage by night. A third group are known as crepuscular: they thrive in the low light of dawn and dusk and remain inactive at other hours."

In an IELTS reading sample by British Council, the paragraph above is followed by this statement:

Most animals are active during the daytime.

In my opinion, the answer is True but the key says Not Given. I can't understand why! Could you help me with this, please?

Answer 1

Perhaps in real life the answer is "true" (I wouldn't know). But we have to provide an answer according to the text. Here, the given statement can be rephrased as

The majority of animals are active during the daytime.

This was not provided in the text. The text specifically says

Numerous creatures, humans included, are largely diurnal

Simply put, numerous means many, but many does not mean most. The text does not specify if in fact "numerous" is equivalent to an amount that would make the majority. For example, imagine that there are one million creatures in existence. If four hundred thousand of them are diurnal, then you could say numerous creatures are diurnal. You could not say most are diurnal because most would require a number greater than five hundred thousand.