pest / rodent control - security deposit

[Kosh Vokter]

My tenants moved out and while cleaning there was evidence of pests in the property. we noticed rat droppings in the garage, around the house etc. the tenants had a dog and chickens, but never notified of rodent activity while occupying the property.  i had to call an exterminator and pay for that. 

Are the $ exterminator costs to clean out pests considered 'cleaning' and thus can be deducted/retained from the security deposit?