Found this in my garden today in Sydney, Australia (specifically Lane Cove). Can you tell me what it is?





Question: Grouping Multiple Raster Layers
Answer: If you aren't looking to mosaic your rasters, it sounds like you just want to group them.  

Have a look at creating a Group Layer on the ESRI help page.

If that doesn't help, perhaps have a look at the Overview of the Raster Toolset on the ESRI help page.