Tenant asked for pest control while it's their responsibility.

[Lulu Heather]

Hello,

I've received a call from my tenants said that they have ants in their dishwasher, they told me: "because their neighbor tenants who live next door spray something, thus the ants came to their place". Last year, they also complained about the ants problem when spring came, even when the unit next to them was vacant.

As in out lease: "Tenant is responsible for keeping the property free of all pests (ants, roaches, fleas, ticks, silverfish, scorpions, etc.) and all routine pest control". But now, they want me to take care of the ants problem for them. Should I say no to them or should I take care of it? Since they have a dog, I'm worried if the ant traps could harm it. 

I would be grateful if you could share your ideas with me. Thank you!