Keep out bugs; harmlessly? im a vegetarian and dont want to snuff out or harm...

im a vegetarian and dont want to snuff out or harm any insects this summer.
i also dont want them surrounded by the house...
is there any means of access to keep insects, such as flys and ants (spiders are generosity in my home), out of my home beside out harming them?
i would preferablly resembling to not use sprays.
i've heard that lavender grease repels bugs, does anyone have experience beside that?
also, i have home-grown lavender plants. how do you put together oil from them?

if you can answer any of these question, it would be most appresiated!
thank you!
Answers:    Having screen mesh on adjectives your windows and peak doors can make a big difference in need harming anything.