Well, not always at first, although, ECID (each cat is different). However, most cats adapt well, and are extremely cooperative. I made these two videos on July 4 to show you how Pearl comes to her testing station and gets a blood test.
In the beginning, the key is to warm the ear first with either a sock that has rice in the toe and is heated a few seconds in the microwave, or with Pearl, I used a damp washcloth in a baggie, heated just 13 or so seconds. I always tested it on MY ear to make sure it was not too hot. I had to hold it on the ear a good 20 to 30 seconds. That did the trick. Believe it or not, after a while you do not need this. The ear learns to bleed.
Another good pointer is to provide a firm surface under the ear. I use my finger. I have rarely poked through. When I tried to use the surface of a rice sock, it gave too much. I like using the device but some people prefer to free hand with a lancet. They hold it at a 45 degree angle; somewhat like sewing. For me, I cannot poke fast enough. But whatever works for you. Try both ways.
Like anything, this takes practice, but once you get a routine down, it's about as much trouble as brushing your teeth and takes considerably less time!