:) this way, the rent will be paid with government money.

For each adopted child, they get a check from government. They will live for free while feeding them with hotdogs.

You may need to have concerns: extra wear and tear in the house, curb appeal of your landscape, more repairment calls, potential leagal implications with the foster home to meet government minimum living standard.

It is better to ask legal opinion from lawer.

If I were you, I will first not allow them to do so, or at least, let them sign indeminty clauses that they can not sue you in the future.