That amount of spiders ,suggest they either have an ample feeding source (other bugs as spiders are somewhat high on the food chain ) or they have simply made your home theirs (Watched that shyt on discovery channel) , ,I did notice I think several roaches on that trap and the fact you are suspicious of a mouse infestation suggests, either you have extremely dirty neighbors or you need to clean your fukking house so I think we can hold off calling the discovery channel for now.
Calling in the landlord may be a good idea .although they might not be happy if this was caused by your actions, and will try to pin the blame on you whatever unless they are ultra nice people,which most landlords are not. You need to weigh things up,personally I would try to sort it myself with rubber gloves, cleaning product and lots of pest killing chemicals, won't be pleasant because I wouldn't want a bad reference if I was planning to continue renting .Do you live with other folks,? they should lend a hand if they are in part responsible. At least give the place a damn good clean if you do decide to contact the landlord to make a better impression.
, unless of course my property was ultra clean ,you could eat your dinner off the floor, in which case, I would be calling in the landlord demanding he/she find out why my property is infested, and calling in environmental health,if he wouldn't let me break the lease.