God forbid if a endangered insect is found on your property.

@Derrek LawsonAround here, corner stores (dépanneurs) are an endangered species, but in parts of the City where there are no supermarkets close-at-hand, they do a booming business ... there is a little one across the street from one of our properties which does over $2M/year in revenue.Survey the neighbourhood, you might want to buy the building which houses the store ... and perhaps the store ... as well. ;-)

Warranty of HabitabilityReal Property Law § 235-bLL in every written or oral residential lease warrants that the premises and common areas are and will be maintained in a condition that is (a) fit for human habitation (b) fit for uses reasonably intended by the parties (c) free from conditions endangering or detrimental to life, health, or safety of occupants.

If they want to break a lease over mold, they have to show evidence that its my fault, and that these mold spores are endangering their health.

Typically HIs are not supposed to endanger themselves in any way, particularly not with high roofs.A drone is used sometimes, but who is going to read the film?

Here's a couple of options of how I would have handled it.Option 1:  The Endangered Species Act1 - Ask them to describe the 3 spiders in detail.2 - When they did, you should become very mad, because...,3 - ...as you will tell them, they killed 3 endangered species of spiders (this is where you give them names, like Gomez, Leggs, and Webmaster), and send them a notice (official looking) stating this and the potential consequences (fines mostly) for doing so.4 - Then you tell them about the 4 other spiders, and yes they have names too, and the 3 mice (with names) and the large rat (fur ball), all on the endangered species list. 

If the tenants are on a term lease VS month to month you can always ask but you have no legal recourse unless they not paying their rent, damaging the property, doing something illegal, endangering others etc...If they are on month to month or the lease has otherwise expired you can give them proper notice (depends on your state what that is, generally 30/60 days) that you are not going to renew their lease. 

Flood zones as mentioned above, and the endangered Scrub Jay zones.

If that were in the lease agreement and they stopped paying, you could still try to evict them for endangering the health of your other tenants.

Is there any chance a 1031 repeal could be retroactive with the Biden regime? TAX! the wealthy is the chant that is getting louder. In Portland, Oregon Ted and Joe are of like minds.