I'd recommend a soil test if you haven't done one in several years. You will learn about your soil including soil type, pH, nutrient levels and more. Knowing the type and fertility of your soil is the starting point to establishing & maintaining a strong turf that can resist diseases, moss, weeds, insects/grubs and look great at an optimal cost. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer
I read 3 concerns about your lawn: ants, grubs & voles:
1) Good info on control of ants in the lawn in the following links:
Ant info - UMN - identification & control info
https://www.canr.msu.edu/ipm/diseases/turfgrass-ant
https://extension.entm.purdue.edu/publications/E-22/E-22.html
2) Grubs (make sure you have them before treating) It's too late for preventive control this year but you can apply insecticides in early September to kill them (curative control).  Read the following:
How to Choose & Apply Grub Control Products-MSU - info on finding & treating
Managing White Grubs in Turfgrass-Purdue 
Take Control of Lawn Grubs w-o chemicals-PSU
Managing grubs in Turf Milky Spore-Illinois
3) Voles are small animals that can be controlled by exclusion, repellants, toxicants, trapping and more, but you must know where they are active.  More info in the attached links:
https://extension.umn.edu/planting-and-growing-guides/vole-damage
Voles - Penn State Extension
https://www.uidaho.edu/-/media/UIdaho-Responsive/Files/Extension/topic/forestry/WL11-Controlling-Vole-Damage.pdf
https://extensionpubs.unl.edu/publication/g887/na/html/view
I hope the above information helps.  Not enough info to comment on lawn turning brown, could be a normal response to summer heat and/or lack of adequate fertilizer and/or grub damage, or something else.  Same for beetles on raspberries.