Background: I sowed my first batch of tomatoes on April 4th on those transparent 12-grid trays w/ domes that are supes trendy right now, potted them up on May 4th & 5th into 3-inch transparent pots (which I now understand may not provide the ideal darkness for their roots, live and learn), and I would like to transplant them outdoors soon.

Questions: One concern that I have (and I'm not sure how concerned I should be) is potentially introducing outdoor wildlife into my indoor environment during the hardening off phase.

• Do other gardeners worry about this or am I over thinking it? Is it basically set them on a table (not on the ground), don't leave them out there for too long, and hope for the best?
• What other steps can I take to keep my indoor environment as sterile as possible while hardening off some plants when they're ready?

ETA Additional Reading: Hardening Off Seedlings: How to Safely Transition Indoor Plants Outdoors