a person or thing that excavates. 2. a power-driven machine for digging, moving, or transporting loose gravel, sand, or soil. 3. a sharp, spoonlike instrument used for scraping out diseased tissue, as in dentistry. Origin of excavator. 1805-1815.
If it is a permanent tattoo, then it would last on the bottom of your toe forever. If it's a temporary tattoo, it would probably only last a day or two.
So no more than a month and you can literally wash it off any time, this is the answer for the common question, how long does a henna tattoo last. Always be sure that you are getting these tattoos, although not the real thing, from someone who is qualified to apply them.