Final answer:
The lizards in Chapter 49 didn't bite Stanley and Zero due to two reasons; the lizards are less aggressive at night and they don't like the taste of onions, which both characters had been eating.
Step-by-step explanation:
The information in Chapter 49 that explains why the lizards didn't bite Stanley and Zero is that the lizards in this chapter are the yellow-spotted lizards, which are known to be lethargic and less aggressive during the night. Onions, which Stanley and Zero had been eating, are mentioned to be repulsive to these lizards. By eating these onions, they have essentially made themselves distasteful to the lizards. Therefore, the lizards didn't bite them because they do not like the taste of onions.
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