If you own a female Monitor, they almost all will lay infertile eggs. You have to have the same large nesting requirements that you would need if there was a male and mating took place or not as she'll need to nest. She will still go through all the motions and need to nest and deposit eggs and it's a big killer (improper nesting) in captive female Monitors. Generally deep soil throughout the cage and a few large tubs with a lid and small hole on top for her to dig into, with the ground being low to mid 80's (F) is adequate. Monitors can be fussy nesters.