Minecraft Hardcore mode, few mobs spawning?

When i first started my hardcore game I had hostile mobs spawning relentlessly in my game, which is of course expected in hardcore mode. Now that I actually have my base well established though almost nothing spawns, anywhere in my map. It started when I decided to go on a quest to find a village so I could hopefully get a large amount of potatoes, carrots, and perhaps melons (was a huge success). I ran around the world for 5 minecraft days, leaving a trail of torches so i could find my way back to my base. On the third day of this journey I noticed no hostile mobs were spawning near my little makeshift house, I didn't think much of it though. While in the village I didn't see a single hostile mob, even zombies who should be attracted to villages, and i stayed there for about 2 minecraft weeks while i planted a sugar farm large enough to get emeralds from a villager buying paper so i could buy the melon slices from another villager. Since I have gotten back to my base it's been another 2 minecraft weeks and I have only seen 1 spider, 3 zombies, 1 creeper, and 2 skeletons in that entire time… Even while mining. I have not been playing my other worlds since I've gotten addicted to this hardcore one, and my difficulty had been on normal before i started playing this world. So I know it isn't the glitch where your last world was on peaceful mode and it effects the hardcore world. I suppose I should just be happy that I have some room to breathe, but like i said my base is well established now, so the most interesting part of the game is the monster killing and the never ending search for diamonds. But I'm very curious why it is that so few mobs are spawning anywhere in my map. Anyone know what causes this or what may fix it?

Added (1). I don't currently have any mods installed for 1.7.4, I have the moar food Mod on forge for 1.6.4 but I'm not playing my forge profile or 1.6.4

Well, i'm not sure what your problem might be, however i know that the most recent optifine mod (you didn't say you were using it but it is common) that it can make to were little to no mobs spawn. If you do have optifine installed that is your problem, other than that i don't know any other bug in the current minecraft that does this (minecraft version 1.7.4 is what i'm referring to) hope this helped.