The first section of Parshat Tazria deals with the Halachot of Tumah and Tahara of people, particularly with regard to childbirth. This follows soon after the presentation of the laws of animal Kashrut and Tumah Vetahara in last week’s Parsha. In explaining why the presentation of the rules of animals precedes that of rules for people, Chazal (Vayikra Rabbah 14:1) teach that when man merits it, he is told that he was first in Creation, but if he lacks merit then he is told that mosquitoes and earthworms preceded him. Clearly, this is a very cryptic comment. To understand this concept, let us use a Mashal, a parable:
A king decided to visit one of the cities in his empire. Before he entered the city, the king’s advisers and supporters arrived there. Nobody would be ludicrous enough to say that those who entered first are more important than the king; quite the opposite – they went first in order to ensure that everything would be ready for the king.
The same is true of man. He arrived in a world that was prepared in his honor. Therefore, despite the fact that other animals were created before him, he is considered more important. However, if he acts like an animal, he is told that mosquitoes and earthworms were created before him. Since he is not acting in a way suited to his status, he loses his importance relative to those that came before him. This is amplified by a statement of the Chatam Sofer, who writes that although man was physically created after everything else, spiritually he was the first to be created. Thus, only by acting in a spiritual manner can man keep his higher status.
While this certainly explains the overall meaning of the Midrash, it still leaves a question: why specifically earthworms and mosquitoes? Rav Baruch Schneerson notes that the two are unique in that mosquitoes (as recorded in Gittin 56a) can not release wastes and that earthworms are destroyed by their own excrement. Since neither can rid themselves of the undesirable, it is as if they are surrounded in badness. Hence, the message man receives when he lacks merit is that he has not discovered the good in life, and is therefore in a comparable state to that of the mosquito and earthworm.