In general, ticks are small, round and grey/brown in colour. They can occasionally get mistaken for skin lumps, but on closer inspection, you should be able to see the tick's legs (speak to your vet if you're unsure).
How do I know if its a tick?
Are there small dark spots on your legs, pants or socks? Ticks crawl upwards onto hosts, beginning at the lower leg and wandering until they find a good spot to attach. If you see small spots on your clothing after being outside, they are likely ticks.
What does a tick mark look like?
The signature rash of a Lyme tick bite looks like a solid red oval or a bull's-eye. It can appear anywhere on your body. The bull's-eye has a central red spot, surrounded by a clear circle with a wide red circle on the outside. The rash is flat and usually doesn't itch.