Every insect's behavior is instinctive; it knows how to act and what to do from the moment it is born.
Is insect's singular or plural and why?
Consider these constructions:
Every man's behavior . . .
Every child's behavior . . .
What about insect's?
So singular
Right. The adjective, "every" denotes a singular noun.
The word "insect" can be used as both a singular and a plural noun. It refers to a single organism of the insect family when used in the singular form, and to multiple organisms of the insect family when used in the plural form.
To determine whether "insect" is being used as a singular or plural noun, we can look at the context of the sentence. In your sentence, the word "insect's" is possessive, indicating ownership. Therefore, it is followed by the singular noun "behavior." This suggests that "insect" is being used in the singular form in this sentence.
If the sentence were to refer to multiple insects' behaviors, it would be written as "Every insect's behaviors are instinctive" since the possessive noun "insects'" is followed by the plural noun "behaviors."
So, in summary, "insect" can be both singular and plural, and the context of the sentence determines which form is being used.