I'm studying a web development unit at University and have noticed that for some reason the .html files i'm writing when opened from finder a duplicate copy of that file is made and placed in that same folder...

for example i have an index.html file and i double click to open the file opens and also create an index copy.html file.

I can't seem to figure out why?! and it's frustrating when am opening a file constantly to check the coding is displaying correctly.

The files have been written using a bunch of different softwares. Tincta, TextWrangler & BBEdit.

anyone out there who can help me decipher this??