With accent marks:
У семи́ ня́нек дитя́ без гла́зу.
~ Seven babysitters make the kid to lose an eye.
The more people take on one task, the less attention is paid to the task.
The closest English equivalent: too many cooks spoil the broth.
Other Russian proverbs
Free cheese is only in a mousetrap.
An old friend is better than two new ones.
Fear has big eyes.
All is well that ends well.
Who is talking about what, and a lousy one about the bath.
Time for business, an hour for fun.
The apple never falls far from the tree.
To live a life is not the same (not as easy) as to go through a field.