For this sentence to be grammatically correct the verb ATTACK needs to be in accordance to the subject "an army of ants" which refers to the third person in singular "it". Therefore, the correct sentence would be as follows: In the 1998 movie Antz an army of ants <u><em>attacks</em></u> a rival group of termites.
It has to be considered the different kinds of subjects there are that refer to <u><em>a</em></u> <u><em>group </em></u><u>of subjects</u>. Grammatically speaking these subjects need verbs in their singular form, for instance: A group of <u><em>students</em></u> <u><em>was </em></u>seen yesterday on the street.
Because speaking in a small group will help them speak in front of people and them giving feedback and them using to improve their presentation will help them to put more confidence into their presentation