Are Macintosh computers like iPad in that you don't have to buy antivirus protection for them?

Are Macintosh computers like iPad in that you don't have to buy antivirus protection for them?

Read more: Are Macintosh computers like iPad in that you don't have to buy antivirus protection for them?

I use an iPad at home and an app named fing to keep track on the number of devices?

… Hooked to my wifi. I've discovered a device named ARRIS I don't seem to be able to identify as part of the family's devices…

Do you know what it may be? (Is another modem of brand ARRIS juicing my network?)

How should I kick it out and prevent it from re-joining my network?

Should I call a pro?

Thanks in advance! :-/

Read more: I use an iPad at home and an app named fing to keep track on the number of devices?