IPhone lies about storage space?

My iPhone says it has no space left. It won't allow me to take pictures with the default camera app, yet it has allowed me to take several dozen photos with Instagram (I discovered this by accident; I use Instagram as my main camera and was surprised to find that the iPhone factory camera app wouldn't work). Why would it say I have "0 bytes" left but still allow me to use the Instagram camera (or Photoshop for that matter, when it saves my edited pics)? I have an iPhone 5S if it matters.

Why don't you put just put some more memory in your phone… Oh wait, you can't coz it's an iPhone… I for idiot… ROFLMAO.

  • Why is my iPhone storage space used so high? I have a 16GB iPhone 4s. I have no songs or videos on it. I have about 32 apps and 500 pictures. My storage space used is at 13.2 GB. Why is that so high? That is almost all of my available data? How can I bring this down? I have a friend with the same phone, same number of pictures and about the same number of apps (maybe a few less) and his storage is only about 4GB used.
  • Why does my iPhone say that I have no storage space? I deleted so many apps and it still says that I have no space. I can't take pictures, download apps, nothing. I've tried turning it off and on and it says the same thing. What can I do to fix it? I'm trying to do everything I can't to restore it.
  • My kitten always lies on my iPhone? My 3 month old kitten insists on laying on my iPhone. He'll headbutt it, purr as hes kneading on it, lick the screen, give love bites to the corner of the case, and lay on it to take naps. Is this normal? I don't really mind (sometimes it gets annoying when I'm trying to text) and he gives a little baby mew when you take it out from underneath him. Anyone else have a kitty who loves technology? And if so, why? I get that computers are warm, but he only goes for my iPhone.
  • My iPhone suddenly went from having 9.4 gb of free space to 7.5 gb of free space? I didn't download any apps or anything, or record any videos or take pictures. I didn't do anything, it just all of a sudden happened today. How can I fix it? I have a 16gb iPhone 5