The enants are experiening a severe infestation of bed bugs ` Is the landlord responsible for extermination costs and also for housing the tenants if need be during extermination.

For bed bugs? Did the landlord furnish the beds?

Can the landlord prove it was caused by the tennants

Normally standard extermination is the cost of the landlord

I see what you are doing, Pesttrackers. Digging up old bed-bug threads and posting your ad on them. And I believe you are in violation of the forum rules.