The process of ecdysis has its hazards. The spider can lose a limb, be unable to extricate itself or fall prey to ants and other predators. If an appendage is lost, it is easily regenerated if lost within the first few moults. The abdomen is dependent on food intake. Smaller spiders undergo fewer moults than the larger spiders.
Males mature one moult before the females to ensure readiness for mating.
The discarded exoskeleton is called an exuvium and retains all the external features of the spider.