I adopted yesterday a pair of 3 month kittens. I was told at shelter that I should confine them to one room for 7-14 days unless they start exploring. The most adventurous of sisters tried to repeatedly sneak past my legs when I enter or leave to get into living room. I'm a bit afraid they she will try to explore outside where catching her will be much more difficult. How can I prevent her from running away and getting lost when I exit my flat?
PS. I'm renting so I can't do too many things which are permanent.
EDIT: They are domestic shorthair and both are very sociable, playful and exploring (after letting them out of carrier they both started exploring with their tail in 'up' position). They both seems to have unlimited amounts of energy as well.