Humasons (ne and old editions) give hints on handling insects.  

However, I did use Tissue Prep II from Fisher for infiltration and embedding,
a harder paraffin to compensate for the chitin in hard exoskeleton.  A regular
processing schedule should work for your ants, mine was longer with the
larger creepy crawlie, whole body of grasshopper with legs removed, they did
not want to see the appendages, just the inside of body.  Takes some
soaking for sectioning (ice water) and very sharp knife, we used high profile
disposables for stability and sharpness.    

I recall using a Bouins type fixative, rapid penetration, and there are
some recommended in Humason X 2.  sorry I can't put my finger on the exact
fixative, it was done in entomology lab, and out of my control.  

Gayle Callis