DIY Rat Infestation: Successful Battle Plans?

[Anastasia Jordan]

I purchased a 3/2 tax sale home. Now that I have moved in I see that the home has a rat infestation. Not mice, large big body brown RATS. 

I'm literally having to go to war.  I'm hearing that pest control companies are expensive. My glue traps are not work (rats flip them over).

Is the basic battle plan to put down poison, put down expensive homedepot traps, and seal entry holes?  I'm waiting for my income tax refund to drop next week and am planning on finishing the rehab on this home in no more than 3 days. I can't have rats here!

Killer part is that there are at least 10 cats surrounding my home. Ain't that supposed to be the first line of defense? 

I will post pictures of the holes and weeds (the jungle) that I have to get rid of.