This is time consuming and you will have lots of layers...

Open image and then open your metalic image (the one to cover the ant)

Select the Transform tool (ctrl+t) and scale to required size, right click to get up menu and select Warp.

Drop opacity of this layer so you can see the ant underneath and using the anchor points, pull and shape the metal image roughly to the shape of the ant.

As you can see, we have a lot of sculpting to do! NAME YOUR LAYERS this is a must. You can start modeling all the leg parts and when this is done select all the layers (hold done ctrl and click all the leg layers) then go to Layer-Group Layers (shortcut ctrl+g) and name this group - legs. Getting into this habbit keeps your layers pallete nice, clean and organized ;-)

You can see below my Group layers. Clicking on the small triangle will open your group so you can carry out any edit you need to do.

Carry on adding and transforming your images until your ant is covered.

Once done, we then move on to shadows. I'm still learning this myself :-) But i thought a bit of burning around joints and also on the body parts (trying to bring the legs forward)

For the small details of legs (the blurred bits)and the hairs, i used a paint brush set to colour of metal (alt click on metal) and painted in. Then using the blur tool go around your image trying to recreate the DOF (depth of field) in the original image.

Once happy save as psd file.
Then flatten layers-( Layer-Flatten Layers)

Make a copy of this layer.
I then played around with some Adjustment Layers.

I used a Photo Filter (warm) and adjusted the settings to try and blend the whole image together.

Once happy i then save this as a JPEG file (call it a different name to the psd file)

Done.