That's interesting. The "insect" probably didn't have human-like thoughts or feelings before parasitizing the boy. That'd mean their species learn from every victim consumed in order to improve their parasitation. If they incorporate the learning into their main body after consuming the parasitized host, that could mean they store learning in the cells. It's the Cellular Memory Theory!
...although in this case this survival strategy seems to have backfired, since clearly the mother is supposed to feed their body to their offspring, but now they learned human fear.