virtualenv activate script missing

I have installed python and virtual environment on linux, but every time I try to create a new virtual environment the bin folder is missing many files such as the activate script. I only succeed if I run the follow command:

sudo virtualenv myvenv

If I only run virtualenv myvenv the bin folder is incomplete.

I have also managed to create a virtual enviroment with python -m venv myvenv

Why is this happening I dont want to use python3, just python. Any ideas?