Hostile mobs seem to spawn in higher light levels than usual. Some of my builds that were mob-proof are no longer mob-proof. I am also hearing pilliger noises no matter where I am in my world (I have indeed used commands to check and there are none around) and finally, none of my friends nor I have found a naturally spawning fox (of course that could just be our luck)

[picture shows light level that mobs can spawn in now that they couldn't before]