All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
What we know from religious texts is that it is forbidden to mock human beings. Allah, The Exalted, says (what means): {O you who have believed, let not a people ridicule (another) people; perhaps they may be better than them; nor let women ridicule (other) women; perhaps they may be better than them. And do not insult one another and do not call each other by (offensive) nicknames. Wretched is the name of disobedience after (one's) faith. And whoever does not repent - then it is those who are the wrongdoers.} [Quran 49:11]
We do not believe that mocking insects or the like is prohibited. However, the Muslim should spend his time in what benefits him in his worldly life and the Hereafter. He should train himself to speak only what is good and refrain from speaking evil words. Maalik cited the following story in a chapter entitled 'Disliked Speech', "It was narrated on the authority of Yahya ibn Sa‘eed that ‘Eesa ibn Maryam (Jesus), may Allah exalt his mention, encountered a pig on the road, so he said to it, 'Go in peace.' Somebody asked, 'Do you say this to a pig?' ‘Eesa replied, 'I fear to accustom my tongue to evil speech.'" [Al-Muwatta']
Allah knows best.